
A safer way than F-Droid to download apps... directly from the source with no middle-man. See: https://www.youtube.com/watch?v=JiN37bn0OE8&t

The best Android apps for privacy and convenience. Open-source preferred. Remember, the most secure way to download an app is from its repo, such as Github. The Google Play store is actually more secure than F-Droid, as long as the app is trustworthy.
All of these have been tested as working on GrapheneOS and Android.
But remember, the more apps, the higher the attack surface.

A safer way than F-Droid to download apps... directly from the source with no middle-man. See: https://www.youtube.com/watch?v=JiN37bn0OE8&t
GrapheneOS is a privacy and security focused mobile OS with Android app compatibility developed as a non-profit open source project. It's focused on the research and development of privacy and security technology including substantial improvements to sandboxing, exploit...




The most secure/private OS to replace Google.
Alternative, CalyxOS:
CalyxOS

I add Izzy to it:
IzzyOnDroid To add it to F-Droid, go to settings and add to repository: https://apt.izzysoft.de/fdroid/ Here is the Repo: https://gitlab.com/IzzyOnDroid/repo
HOWEVER, it is not the most secure way to add apps. More privacy, but not more secure. Not only are they updated less frequently, but it is not as secure as downloading from a repo like on GitHub (you can set up something like an RSS feed to get notified of new updates to download for your apps).
K-9 is an open source email client for Android with multi-folder sync, email signatures, Bcc-to-self, return-address configuration, keyboard shortcuts, Exchange Support, message flagging, IMAP deletes, saving attachments, configurable notifications and more.




The best mail client for Android. Open-source.
You can encrypt mail with an add-on app, OpenKeychain:
OpenKeychain
Cross-platform email client providing POP/IMAP support, robust filtering, multiple accounts, and chat. Extendable via add-ons with RSS/Atom, etc.





They have a new app built from K-9 on Android, and I assume it will eventually replace K-9 completely. It offers seamless porting from your accounts on desktop to Android, which is quite convenient.
Open-source password manager with AES-256 encryption and device sync. Store and access encrypted logins across platforms like iOS and Android.





Cross-platform password manager
Alternatively, Proton Pass:
Proton Pass Buttercup:
Buttercup Lesspass:
LessPass
Aegis Authenticator is a free, secure and open source app to manage your 2-step verification tokens for your online services.




Open source authenticator for Android only.
Recommend 2FAS if you want on iPhone also.
Alternatively and for iPhone as well,
- 2FAS (also has browser extension:
2FA Authenticator (2FAS) (backup via encrypted folder on Google Drive (not automatic android backup) or manual encrypted file, app lock, browser extension (wouldn't recommend for security), import, blocks screenshot with timer to allow).
- FreeOTP:
FreeOTP (backup via Android Google automatic backup, or download ecrypted backup file. However, password cannot be changed later, and no 2fa itself, like email or phone.) Authenticator Pro:
Stratum (only Android)
Okay, but above are better,
- Bitwarden Authenticate:
Bitwarden Authenticator (android automatic backups or manual unencrypted file backups. Only biometric app password. )
Not recommended, based in India, can't see client-side what is happening, requires login:
- ente Authenticator:
Ente Auth
OpenVPN Connect provides flexible VPN solutions to secure your data communications, whether it's for Internet privacy, remote access for employees, securing IoT, or for networking Cloud data centers.





Open-source VPN client. Works with every trustworthy VPN provider. Preferable to closed-source apps.
Alternatively, and faster than OpenVPN, but not all VPN providers use it yet, WireGuard:
WireGuard
Alternatively, a proxy, Shadowsocks:
Shadowsocks
But consider making your own VPN with a VPS: https://gist.github.com/joepie91/5a9909939e6ce7d09e29
List of some good VPN: https://offshore.cat/vpn
An OpenSnitch-inspired firewall and network monitor + a pi-hole-inspired DNS over HTTPS client with blocklists.




DNS + Firewall. Open-source. Be aware that alternative DNS opens you up to being fingerprinted as you don't blend in as well.
Alternatively, (though none other than RethinkDNS allow simultaneous usage with a VPN protocol like Wireguard from my knowledge. they may or may not allow the use of proxies). TrackerControl:
TrackerControl AdGuard:
AdGuard Blokada:
Blokada
Privacy and security enhanced releases of Chromium for GrapheneOS. Vanadium provides the WebView and standard user-facing browser on GrapheneOS.


Currently the most secure browser on Android (need GrapheneOS).
This is a privacy oriented and deblobbed web browser based on Mozilla Firefox technology. It enables many features upstreamed by the
Tor Uplift project using preferences from the arkenfox-user.js project.


Good, private browser for Android
Alternatively, a Chromium-based browser, Cromite:
Cromite
An end-to-end encrypted note-taking by Proton. Offline access, unlimited sync across devices, tagging, passcode and biometric security, plus advanced premium privacy features.





Cross-platform, private and open-source note-taking app that syncs across devices.
Android keyboard for secure E2EE communication through the signal protocol in any messenger. Communicate securely and independent, regardless of the legal situation or whether messengers use E2EE.




A secure collaboration app with end-to-end encryption and interoperability across web, desktop, and mobile. Includes chat, voice, and video calls.





A secure and private messaging app that does not require a phone number.
For even more security (but not plug and play), Briar:
Briar
An encrypted messaging app focused on privacy, supporting texts, calls, photos, videos, files, and group chats, with no ads or trackers.





One of the most secure messaging apps, even endorsed by Snowden. However, at this time you have to use a phone number.
Experience instant messaging with remarkable speed and robust security. Join massive group chats or channels. Enjoy free and advanced features.





The most convenient messaging app that lets you delete messages at any time, and supports extremely large groups.
Alternatively, a few different (sometimes less) features and faster and still official app, TelegramX:
Telegram X
Alternatively for a web app (there are a few of these you can find on telegram.org), Telegram Web A:
Telegram Web A
Alternatively for more features, but not official and some controversy with developers (use at own risk), NekoGram X:
NekoGram X
Cross-platform, free media player supports multimedia files, DVDs, streaming, offers hardware acceleration, 4K, lossless audio, and more.





Works well. Unlike Desktop, it remembers your place by default. Good for playing audiobooks while driving or watching videos.
Markor is a TextEditor for Android, versatile, flexible, and lightweight. Markor utilizes simple markup formats like Markdown and todo.txt for note-taking and list management. It is versatile at working with text; it can also be used for keeping bookmarks, copying to clipboard...




Simple text editor that supports both .txt and .md, so you can use it with notebooks like Zim Wiki or Obsidian if you sync them on the cloud.





Use this for raw photos.
If you are using Graphene, you may also want Google's proprietary camera app, Google Camera:
Google Camera
Imagepipe - Reduces image size and removes exif-tags when sharing images on android devices.



Open-source app that reduces image size and wipes metadata from images before sending.
Screenshot Tile offers a variety of features designed to enhance your experience when taking and managing screenshots. One of the key benefits of our app is the ability to customize storage location, format, and notification settings to suit your preferences.


Nice screenshot app you can use. You can add it to your quick settings tiles in the notification shade at the top, as an overlay, or by pressing buttons like you normally might.
Then it lets you drag a box rather than having to crop later (but can also snap the entire screen).
Quite efficient for meming.
Kotlin Multiplatform Music Downloader, Supports Spotify / Gaana / Youtube Music / Jio Saavn.



Lightweight and open-source app for YouTube, PeerTube, SoundCloud, and more. No Google Account needed, supports 4K and background audio streaming with downloads.




The OSS Document Scanner is a free and Open Source app to transform your mobile device into a powerful document scanner.





Turn photos of documents into small .pdf/.jpg. Good at making them look like black/white or color scans and cleaning up imperfections.
Open-source, and edits into a small file even better than CamScanner. But at least on GrapheneOS, it doesn't take the photos well, so I take photos with the normal camera first.
For a good proprietary option, but full of ads and not pro-privacy, CamScanner:
CamScanner
With EDS (Encrypted Data Store) you can store your files in the encrypted container to prevent unauthorized access to sensitive information.





Supports your Veracrypt containers on Android. Open-source.
Orbot is a freely licensed open-source application developed for the Android platform. It acts as a front-end to the Tor binary application, and also provides an HTTP Proxy for connecting web browsers and other HTTP client applications into the Tor SOCKS interface.



Collects and analyzes mobile radio data to detect threats like IMSI catchers, user tracking, and SS7 attacks on supported Qualcomm-based, rooted Android devices.



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.






This tool helps you detect potential "man-in-the-middle" attacks by comparing the security fingerprints of your SSL certificate with the one seen from a trusted external network. If the fingerprints don't match, it suggests someone might be tampering with your internet traffic.



TrackerControl allows users to monitor and control the widespread, ongoing, hidden data collection in mobile apps about user behaviour ('tracking').




Allows users to monitor and control the widespread, ongoing, hidden data collection in mobile apps about user behavior ('tracking').
Alternatively, Exodus:
Exodus Privacy
ReThink DNS above may have much of the same features already, but TrackerControl may have some different information present and finetuning.
Hypatia is the world's first FOSS malware scanner for Android. It is powered by ClamAV style signature databases.




ClamAV antivirus for Android. Open-source
URLCheck acts as an intermediary when opening url links, allowing, among other things: to remove trackers, affiliate links, unnecessary elements, facilitating link sharing, protecting against certain phishing techniques and many more….




Set this as your default browser to automatically clean links of trackers and then open them in your browser of choice.
Alternatively, Leon:
Léon – The URL Cleaner




Freeze apps (even some system apps) that you do not use. Save battery, increase security. Open-source.
Koodous Query is a tool developed by Koodous, a platform specialized in the detection and analysis of malicious software. Its main function is to allow users to search for information on APK files through batches of hashes.





Scan .apk files and Android threat protection
Monitor GSM/CDMA/LTE network: current and neighboring cell infos, signal strength. Multi SIM support (when possible). Use GPS/geolocation. Generate database with custom info on cells. Export log to file CLF/KML. Map shows cell location. List WiFi access points.



🔔 Get the famous "Recording Indicators" feature of iOS14 to android. Get notified every time a third-party app or a service uses camera or microphone. - GitHub - NitishGadangi/Privacy-Indicator-App: 🔔 Get the famous "Recording...







Find out if someone is tracking you. May decrease battery. Open-source
On-premises file sync, universal access, integrated collaboration, real-time communication with privacy and data control focus.





Open-Source Cloud Storage
Alternatively, OwnCloud:
ownCloud
For a good free, proprietary, but privacy-respecting option, kDrive:
kDrive ProtonDrive:
Proton Drive Filen:
Filen
For a different sync option, Syncthing:
Syncthing
Greentooth can help you save battery and mitigate the security risks of Bluetooth by automatically turning Bluetooth off when it is no longer needed. When the last Bluetooth device has disconnected Greentooth will wait for an adjustable amount of time in order to not disturb any...



Auto-shut off bluetooth when not in use for security and battery. Open-source.
Not needed with GrapheneOS now, as this option is built-in.
FUTO Voice Input is an application that lets you do speech-to-text on Android, integrating with third party keyboards or apps that use the generic speech-to-text APIs.







Small and lightweight, open-source calculator and converter.
Breezy Weather is a weather app with a strong focus on design, with a simple, clean UX, smooth animations, and Material Design all over, plus lots of customizability.



Introducing our keyboard-based launcher that can help streamline your workflow and improve productivity. The launcher offers a minimalist and fast approach to accessing your favorite apps, files, and folders, which can save you time and effort.




A quick, text-based launcher. You don't have to use it as a launcher. You can also set a widget.
Comments
The Mull browser is no longer supported. I recommend its active fork, IronFox.
I recently discover Alibi which is a great Echo alternative. There is also FadCam but not similar enough imo
Thanks, replaced Echo with Alibi.
Thanks! I've been searching for a FOSS document scanner for so many years now. OSS Document Scanner will be replacing Microsoft Lens for me.