Good Open Source Android Apps

  • Lineage OS icon

    Lineage OS

    Free Android Website

    A free and open-source operating system for smartphones and tablet computers, based on the Android mobile platform. It is the successor to the highly popular custom ROM CyanogenMod, from which it was forked in December 2016 when Cyanogen Inc. announced it was discontinuing development and shut down the infrastructure behind the project. Since Cyanogen Inc. retained the rights to the Cyanogen name, the project rebranded its fork as LineageOS.

    LineageOS was officially launched on December 24, 2016, with the source code available on GitHub. Since that time, LineageOS has been described as highly popular and forcibly developed; within 4 months from the initial announcement, LineageOS development builds covered more than 160 models of phone, and over a million users, having doubled its user base in the month February–March 2017.


  • Replicant icon


    Free Android Website

    Replicant is a distribution of Android that is 100% Free Software.

    Most of Android is licensed freely under the Apache License 2.0. The Linux core is mostly Free Software under the GPLv2. However, there are numerous components of the default software stack on the devices that are proprietary software. Most notably, nearly any component that touches the hardware directly is proprietary software. Replicant lacks location tracking (anti)features.

    On the Replicant Wiki you can find a list of open source apps that can be used to replace the proprietary Google apps (Market, Gmail, Maps, etc.). Most notably, it suggests to use F-Droid instead of Google Market.


  • CopperheadOS icon


    Free Android Website

    A hardened open-source operating system based on Android with PaX, OpenBSD malloc and much other privacy/security features.


  • FBReader icon


    Free Mac OS X Windows Linux Android iPhone ... S60 Blackberry Android Tablet BSD iPad Website

    FBReader is an e-book reader for various platforms.


    Supported e-book formats are:
    ePub, an international e-publishing standard.
    fb2, a Russian e-books standard de facto.
    Non-DRM'd version of Mobipocket, a popular commercial e-book format (Small Mobipocket eBook Reader iconMobipocket eBook Reader).
    plain text is supported, however FBReader might not always correctly split text into paragraphs.
    some subsets of RTF and MS Word Doc.

    Direct reading from tar, zip, gzip and bzip2 archives. (Multiple books in one archive are supported.)
    Automatic library building.
    Automatic language and character encoding detection is supported.
    Automatically generated contents table.
    Embedded images support.
    Footnotes/hyperlinks support.
    Position indicator.
    Keeps the last open book and the last read positions for all opened books between runs.
    List of last opened books.
    Automatic hyphenations. Liang's algorithm is used. The same algorithm is used in TeX, and TeX hyphenation patterns are used in FBReader. Patterns for Czech, English, Esperanto, Finnish, French, German, Italian, Norwegian, Portuguese, Russian, Spanish, Swedish and Ukrainian are included in the current version.
    Text search.
    Full-screen mode.
    Screen rotation by 90, 180 and 270 degrees.

    Currently FBReader works on

    Linux desktop.
    Windows XP/Vista computer.
    MacOS X (port of Stanislav Gobunov).
    FreeBSD computer.
    Various linux-based mobile devices:
    Sharp Zaurus with Qtopia-based ROMs, pdaXrom or OpenZaurus ROM.
    Archos PMA430.
    Siemens Simpad with Opensimpad 0.9.0/Opie ROM.
    Nokia 770/N800/N810 Internet Tablets (maemo).
    PepperPad 3 handheld web computer.
    Motorola A1200 smartphone.
    Motorola E680i/A780 smartphones. (This port is available from the third-party site.)
    IRex iLiad. (This port is available from the third-party site.)


  • LibreOffice icon


    Free Mac OS X Windows Linux Android BSD Website

    LibreOffice is a free and open-source office suite that is compatible with other major office suites, and is available on all operating systems. It is an independently-developed version of the suite.

    The office suite includes:

    Small LibreOffice - Writer iconLibreOffice - Writer, a word processor with similar functionality and file support to Small Microsoft Office Word iconMicrosoft Office Word . It has extensive WYSIWYG word processing capabilities, but can also be used as a basic text editor.

    Small LibreOffice - Calc iconLibreOffice - Calc , a spreadsheet program, similar to Small Microsoft Office Excel iconMicrosoft Office Excel . It has a number of unique features, including a system which automatically defines series of graphs, based on information available to the user.

    Small LibreOffice - Impress iconLibreOffice - Impress , a presentation program resembling Small Microsoft Office Powerpoint iconMicrosoft Office Powerpoint . Presentations can be exported as SWF files, allowing them to be viewed on any computer with Adobe Flash installed.

    Small LibreOffice - Draw iconLibreOffice - Draw , a vector graphics editor and diagramming tool similar to Small Microsoft Office Visio iconMicrosoft Office Visio . It provides connectors between shapes, which are available in a range of line styles and facilitate building drawings such as flowcharts. It also includes features similar to desktop publishing software such as Small Scribus iconScribus and Small Microsoft Office Publisher iconMicrosoft Office Publisher .

    Small LibreOffice - Math iconLibreOffice - Math , an application designed for creating and editing mathematical formulae.
    Small LibreOffice - Base iconLibreOffice - Base , a database management program, similar to Small Microsoft Office Access iconMicrosoft Office Access .


  • MuPDF icon


    Free Windows Linux Android iPhone iPad ... Xfce Website

    MuPDF is a lightweight PDF and XPS viewer.

    The renderer in MuPDF is tailored for high quality anti-aliased graphics. It renders text with metrics and spacing accurate to within fractions of a pixel for the highest fidelity in reproducing the look of a printed page on screen.

    MuPDF is also small, fast, and yet complete. It supports PDF 1.7 with transparency, encryption, hyperlinks, annotations, searching and more. It also reads OpenXPS documents.

    We don't support interactive features such as form filling, javascript and transitions. MuPDF is written modularly, so such features can be added on by integrators if they so desire.


  • LibreTorrent icon


    Free Android Website

    LibreTorrent is a Free as in Freedom torrent client for Android 4 and later, based on libtorrent. Download and share files directly on your device.

    Implemented features:

    • DHT, PeX, encryption, LSD, UPnP, NAT-PMP, µTP
    • IP filtering (eMule dat and PeerGuardian)
    • Ability to fine tune (network settings, power management, battery control, UI settings, etc.)
    • Supports torrents with large number of files and big files
    • HTTP\S and magnet links support
    • Tor support (using Orbot)
    • Support proxy for trackers and peers
    • Ability to move files while downloading
    • Ability to automatic movement of files to another directory or to an external drive at the end of download
    • Ability to specify file and folder priorities
    • Ability to select which files to download
    • Ability to download sequentially
    • Material Design
    • Tablet optimized UI


  • Orbot icon


    Free Android Android Tablet Website

    Orbot is an open source Small Tor iconTor Proxy App for Small Android iconAndroid Phones. If the phone is rooted, it can even transparently route all phone internet traffic through the Small Tor iconTor network. Should be installed alongside Orweb, an open source Tor web browser that will automatically use Orbot.


  • ProtonMail icon


    Freemium Web Android iPhone iPad Website

    Secure email with absolutely no compromises, brought to you by MIT and CERN scientists.

    Swiss Based
    ProtonMail is incorporated in Switzerland and our servers are located in Switzerland. We are outside of US and EU jurisdiction and all user data is protected by strict Swiss privacy laws.

    Zero Access
    Because of our end-to-end encryption, your data is already encrypted by the time it reaches our servers. We have no access to your messages, and since we cannot decrypt them, we cannot share them with third parties.

    Backwards Compatible
    ProtonMail works out of any modern web browser, there is nothing to install. We are also backwards compatible with other email providers so you can continue sending and receiving emails from friends who are not using ProtonMail.

    Forever Free
    We believe privacy is a fundamental human right and should be available for everyone. That's why we offer multi-tiered pricing including a free version that anyone can use. Let's bring privacy back to the people!

    Fully Anonymous
    We do not log IP addresses or require any personal information to sign up. We accept bitcoin and cash payments for paid accounts to ensure even paid account users have complete privacy.

    Cross Platform
    ProtonMail works on all devices, including desktops, laptops, tablets, and smartphones. It's as simple as visiting our site and logging in. There are no plugins or apps to install - simply use your favorite web browser.


  • FreeOTP icon


    Free Android iPhone Android Tablet iPad Website

    FreeOTP is a two-factor authentication application for systems utilizing one-time password protocols with support for ?Android (3.0 or later) and ?iOS (7 or later). Tokens can be added easily by scanning a QR-code or by manually entering in the token configuration.

    FreeOTP implements open standards. This means that no proprietary server-side component is necessary: use any server-side component that implements these standards. We personally recommend ?FreeIPA, which uses TOTP. However, any standards-compliant implementation will work. Currently, FreeOTP provides implementations of ?HOTP and ?TOTP.


  • F-Droid icon


    Free Web Android Android Tablet Website

    The F-Droid Repository is an easily-installable catalogue of free and open source apps for Android. With F-Droid, it's easy to browse and install apps on your device, and keep track of updates. You can also browse the repository with a web browser, and download the app directly from there, if you can’t or don’t want to run the F-Droid client on your device.

    All applications in the default repository must be Free and Open Source software – for example, released under a GPL or Apache license. Every effort is made to verify that this is actually the case, both by visual inspection of the source, and by building the application from the published source.

    Software that reports user activity without permission (e.g. via Google Analytics) or tracks user behaviour (e.g. most advertising platforms) is specifically excluded from FDroid’s own repository, as is software with the primary purpose of interacting with a non-Free network service. You are, of course, free to set up your own repository for this kind of software – the server source is available, and the client will allow addition or removal of repositories as you see fit.

    F-Droid originated as a fork of Aptoide. F-Droid can be installed from its website or from within Aptoide, but it is not available for download in Google Market.


  • icon

    Free Android Kindle Fire Website

    Protect your communication in transit and on your phone. SMSSecure is a full replacement for the default text messaging application: all messages are encrypted locally and messages to other SMSSecure users are encrypted over the air.


  • NewPipe icon


    Free Android YouTube Website

    NewPipe is a lightweight YouTube front-end for Android.

    It doesn't need the YouTube-API or any Google Play Services, as NewPipe only parses the YouTube website in order to gain the information it needs.
    Therefore this app can be used on devices without Google Services installed. Also, you don't need a YouTube account to use NewPipe, and it's FLOSS.


    Search videos
    Display general information about a video
    Watch YouTube videos
    Listen to YouTube videos (experimental)
    Select the streaming player to watch the video with
    Download videos
    Download audio only
    Open a video in Kodi
    Show Next/Related videos
    Search YouTube in a specific language
    Watch age restricted material
    Display general information about channels


  • AFWall+ icon


    Free Android Website

    AFWall+ is an improved version of Small DroidWall iconDroidWall (front-end application for the powerful iptables Linux firewall). It allows you to restrict which applications are permitted to access your data networks (2G/3G and/or Wi-Fi and while in roaming).
    Note: If DroidWall/Avast doesn't work on your device, AFWall+ also will not work.


  • Android IMSI-Catcher Detector icon

    Android IMSI-Catcher Detector

    Free Android Website

    AIMSICD is an Android app to detect IMSI-Catchers. These devices are false mobile towers (base stations) acting between the target mobile phone(s) and the real towers of service providers. As such they are considered a Man-In-The-Middle (MITM) attack. This surveillance technology is also known as "StingRay", "Cellular Interception" and alike. Find out more in our Wiki on GitHub.

    AIMSICD attempts to detect IMSI-Catchers through detection methods such as these:
    Check Tower Information Consistency
    Check LAC/Cell ID Consistency
    Check Neighboring Cell Info
    Prevent silent app installations
    Monitor Signal Strength
    Detect silent SMS
    Detect FemtoCells

    Why use it ?
    The FBI or local police regularly deploys IMSI-Catchers hidden in vehicles at protests to obtain a record of everyone who attended with a cell phone (leave your phones at home by all means if you really have to attend). IMSI-Catchers also allow adversaries to intercept your conversations, text messages, and data. Police can use them to determine your location or to find out who is in a given geographic area at what time. Identity thieves can use freely available tools and even build their own rogue GSM BTS to monitor and manipulate communications from a parked car in your residential neighborhood - notably for stealing passwords or credit card data from people nearby who make purchases on their phones. The reason IMSI-Catchers are so commonly used is that it is very easy to get away with using them since they leave no traces. Our app aims to make it possible to detect the IMSI-Catchers so that using them becomes a risky proposition. It also aims to make users safer by alerting on possible interception and tracking. Fight for your privacy!


  • Haven icon


    Free Android Website

    Haven is for people who need a way to protect their personal spaces and possessions without compromising their own privacy. It is an Android application that leverages on-device sensors to provide monitoring and protection of physical spaces. Haven turns any Android phone into a motion, sound, vibration and light detector, watching for unexpected guests and unwanted intruders. We designed Haven for investigative journalists, human rights defenders, and people at risk of forced disappearance to create a new kind of herd immunity. By combining the array of sensors found in any smartphone, with the world’s most secure communications technologies, like Signal and Tor, Haven prevents the worst kind of people from silencing citizens without getting caught in the act.

    Safety through Sensors

    Haven only saves images and sound when triggered by motion or volume, and stores everything locally on the device. You can position the device’s camera to capture visible motion, or set your phone somewhere discreet to just listen for noises. Get secure notifications of intrusion events instantly and access the logs remotely or anytime later.

    The follow sensors are monitored for a measurable change, and then recorded to an event log on the device:
    • Accelerometer: phone’s motion and vibration
    • Camera: motion in the phone’s visible surroundings from front or back camera
    • Microphone: noises in the enviroment
    • Light: change in light from ambient light sensor
    • Power: detect device being unplugged or power loss


  • OpenKeychain icon


    Free Android Android Tablet K-9 Mail Website

    OpenKeychain helps you communicate more privately and securely. It uses high-quality modern encryption to ensure that your messages can be read only by the people you send them to, others can send you messages that only you can read, and these messages can be digitally signed so the people getting them are sure who sent them. OpenKeychain is based on the well established OpenPGP standard making encryption compatible across your devices and operating systems.

    Modern encryption is based on digital “keys”. OpenKeychain stores and manages your keys, and those of the people you communicate with, on your Android. It also helps you find others’ keys online, and interchange keys by touching devices. But its most frequent use is in using those keys to encrypt and decrypt messages.


  • Open Camera icon

    Open Camera

    Free Android Android Tablet Website

    Open Camera is an Open Source Camera app for Android phones and tablets. Features:

    Option to auto-stabilise so your pictures are perfectly level no matter what.
    Expose your camera's functionality: support for focus modes, scene modes, color effects, white balance, ISO, exposure compensation/lock, face detection, torch.
    Video recording (supports all available resolutions including HD).
    Handy remote controls: timer (with optional voice countdown), auto-repeat mode (with configurable delay).
    Option to take photo remotely by making a noise (e.g., voice, whistle), or by voice command "cheese".
    Configurable volume keys.
    Optimise GUI for left or right-handed users.
    Zoom via multi-touch gesture and single-touch control.
    Ability to lock orientation to portrait or landscape for photo or video.
    Choice of save folder (including support for Lollipop's Storage Access Framework).
    Disable shutter sound.
    Overlay a choice of grids (including "rule of thirds") and crop guides.
    Optional GPS location tagging (geotagging) of photos and videos; for photos this includes compass direction (GPSImgDirection, GPSImgDirectionRef).
    Apply a date and timestamp, location coordinates, and custom text to photos; store date/time and location as video subtitles (.SRT).
    Yes you can take a selfie (also known as front camera), includes support for "screen flash".
    Support for (some) external microphones.
    Widget to automatically take a photo after launching.
    Support for Android 5 Camera2 API: manual focus distance; manual ISO; manual exposure time; RAW (DNG) files.
    Support for HDR and Exposure Bracketing (Camera2 only).
    Dynamic range optimisation mode for better quality photos.
    Small file size.
    Completely free, and no ads in the app. Open Source.


  • AdAway icon


    Free Android Website

    An ad blocker that uses the hosts file. The hosts file contains a list of mappings between hostnames and IP addresses. When an app requests an ad, that request is directed to which does nothing. There are options to run a web server to respond to blocked hostnames and to direct requests to the IP address of your choosing. You can automatically download hosts files from the app but it is possible to use your own and to add certain sites to the white- and black-lists.


  • AntennaPod icon


    Free Android Website

    AntennaPod gives you access to millions of free and paid podcasts, from independent podcasters to large publishing houses such as the BBC, NPR and CNN. Add, import and export their feeds hassle-free using the iTunes podcast database, OPML files or simple RSS URLs. Save effort, battery power and mobile data usage with powerful automation controls for downloading episodes (filtering episodes, specify times, intervals and WiFi networks) and deleting episodes (based your favourites and delay settings).

    But most importantly: Download, stream or queue episodes and enjoy them the way you like with adjustable playback speeds, chapter support and a sleep timer. You can even show your love to the content creators with our Flattr integration.

    Made by podcast-enthousiast, AntennaPod is free in all senses of the word: open source, no costs, no ads.

    All features:

    • Add and import feeds via the iTunes and directories, OPML files and RSS or Atom links
    • Manage playback from anywhere: homescreen widget, system notification and earplug and bluetooth controls
    • Enjoy listening your way with adjustable playback speed, chapter support, remembered playback position and an advanced sleep timer
    • Access password-protected feeds and episodes
    • Take advantage of paged feeds ( )

    • Mark episodes as favourite
    • Share episodes and feeds through advanced social media and email options, the services and via OPML export
    • Support content creators with Flattr integration including automatic flattring

    • Take control over automated downloading: choose feeds, exclude mobile networks, select specific WiFi networks, require the phone to be charging and set times or intervals
    • Manage storage by setting the amount of cached episodes, smart deletion and selecting your preferred download location
    • Back-up your subscriptions with the integration and OPML export


  • Slide for Reddit icon

    Slide for Reddit

    Free Android Website

    Slide for Reddit is a rock-solid material-designed unofficial browser for Reddit with an easy to use UI and tons of customization. Slide is ad-free, open source, and is packed with many unique features!

    Major features
    • Browse Slide fully offline! There is no longer a need to have an offline browser installed
    • Subreddit colors (make each sub unique!)
    • 12,000 theme combinations, make Slide truly unique!
    • View images, gifs, albums,, Streamable, Gyfcat, and Imgur links in the app
    • Support for Live Threads
    • Full moderation suite
    • Reply to comments and submissions inline, and upload images straight to your submissions/comments
    • Filters support (link, text, title, and subreddit)
    • Edit and create Multireddits
    • Four view modes: View huge cards with images or super-compact desktop mode for power users!
    • Data-saving options with quality selection
    • Synccit integration
    • Ad-Block in websites (Pro)
    • Paging Shadowbox and vertical Gallery view modes (Pro)


  • Transportr icon


    Free Android Website

    Transportr is the public transport companion that respects your privacy and your freedom. Transportr is a non-profit app developed by people around the world to make using public transport as easy as possible wherever you are. Currently, it works best in Europe, but also supports many places world-wide. If you live in an unsupported area, consider adding it to Transportr. It finds directions from your home, your current position or a given station to wherever you want to go. You can also save entire trips as favorites and find next trips with one click. Discover nearby stations and show upcoming departures including the delays (if there are any).


  • Tomahawk icon


    Free Mac Windows Linux Android Website

    Tomahawk gives you to access to all of your favorite music in one powerful media player. Seamlessly jump from playing a song off your local machine, to one streaming from your other machines, to a recommendation from Spotify, to a pre-release on SoundCloud to your favorite indie band on Jamendo.

    Tomahawk lets you plug-in multiple content sources, connect to your friends across a range of networks and breaks down the barriers between true social music experiences by enabling data portability and sharing across music services and licensing territories.


    Stop chasing your music across different machines, services and websites. No matter where your content is, Tomahawk can find it and play it.

    Think of it as "antiTunes". It's a music player that is optimized for one thing... to play, discover and share music.

    Connect to your other machines and friends via Jabber, Google Chat and Twitter. Browse and play their libraries, playlists and stations.

    Cross Platform
    A Mac connected to Windows machine connected to a Linux machine? Sure... no problem. Betas are now available for OS X, Windows & Linux.

    Custom Stations
    Yeah, it's like a "genius" playlist... only smarter, and continuous. Whatever you are in the mood for, we've got the knobs and dials to find it for you.

    Check out the Tomahawk ecosystem that already exists, pretty cool, eh? And we are just getting started. How about you join us?

    Playlist Importer
    Metadata from playlists from all over the web - and other media players - can easily be imported into Tomahawk.

    Tomahawk is totally Free & Open-Source Software.


  • OpenLauncher icon


    Free Android Website

    This an open source Android launcher project, started from scratch. We aim to create a powerful and community driven Android launcher.


  • Signal icon


    Free Mac OS X Windows Linux Android iPhone ... Android Tablet iPad Chrome Website

    TextSecure and RedPhone have been merged to create Signal!

    Using Signal, you can communicate instantly while avoiding SMS fees, create groups so that you can chat in real time with all your friends at once, and share media or attachments all with complete privacy. The server never has access to any of your communication and never stores any of your data.

    • Say Anything - Send high-quality group, text, picture, and video messages, all without SMS and MMS fees.
    • Speak Freely - Make crystal-clear phone calls to people who live across town, or across the ocean, with no long-distance charges.
    • Be Yourself - Signal uses your existing phone number and address book. There are no separate logins, usernames, passwords, or PINs to manage or lose.
    • Stay Secure - We cannot hear your conversations or see your messages, and no one else can either. No exceptions. You can even tap and hold on a contact's name to see advanced identity verification options. Everything in Signal is always end-to-end encrypted and painstakingly engineered in order to keep your communication safe.
    • Go Fast - Signal is optimized for speed without compromise. Our state-of-the-art Axolotl protocol is unmatched in its performance, strength, and reliability.
    • Remain Connected - Push notifications let you know when new messages have arrived, and they'll be waiting for you even if your battery dies or you temporarily lose service.
    • Get Organized - Unique archive functionality makes it easy to keep track of the conversations that matter to you right now.
    • Pay Nothing - Signal is supported by a team of dedicated developers, community donations, and grants. There are no advertisements, and it doesn't cost anything to use.
    • View Source - All of our code is free, open, and available on GitHub ( ).
    • Join Movements - Technology developed by Open Whisper Systems is trusted and used by millions of people around the world every day.


  • Amaze File Manager icon

    Amaze File Manager

    Free Android Android Tablet Website

    Amaze File Manager is an intuitive, open-source file manager for Android that's both free and ad-free (no upgrade offers, no popups, no ads at all). It's based on Material Design guidelines so it sits very nicely alongside the stock Android experience from Google and being open-source, concerns about privacy and security, should they exist, can easily be addressed.


    • No ads at all
    • Lightweight and super fast
    • Based on Material Design guidelines
    • Basic features like cut, copy, delete, compress, extract etc. easily accessible
    • Work on multiple tabs at same time
    • Multiple themes with cool icons
    • Navigation drawer for quick navigation
    • App Manager to open, backup, or directly uninstall any app
    • Quickly access history, access bookmarks or search for any file
    • Root explorer for advanced users