F-Droid is an awesome app repository for FOSS (Free & Open Source Software) android apps. From productivity apps to games, f-droid has (almost) everything you need. Hope you will discover useful FOSS apps to free your phone from Big Tech^^
This list includes apps from the official f-droid repo but also from IzzyOnDroid and some customs repositories which will be always linked so you can add them easily.
Privacy focused OS for everyone My privacy and user friendly setup
For more FOSS Android apps check : Beautiful Open Source Apps for Android
Adding custom repo might not be as secure as the official one so I'm not responsable if you encounter any problems with them ! I encourage you to do your own research about it !
Also while open source is great for privacy and security it is not perfect. So keep that in mind before downloading any apps. Most apps that I've listed are privacy friendly but some might be not be perfectly private and secure. I again encourage you to do your own research about them.
I am not a privacy and security expert. I'm also don't consider myself as a developper so I do not have any technical knowledge and so I didn't look into any source code of any apps in this list !
English is not my mother tongue ^^'
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...
PGP made easy. Encrypt e-mail, WhatsApp messages or whatever texte you want with this amazing tool.
Cryptomator provides transparent, client-side encryption for your cloud. Protect your documents from unauthorized access. Cryptomator is free and open source software, so you can rest assured there are no backdoors.
NOT ON THE OFFICIAL REPO ! Cryptomator repository IzzyOnDroid repo
Encrypt your data before uploading them in the cloud.
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...
Features a passive jammer technique that engages the microphone thereby blocking other apps from using it. But does NOT listen to or record any of the audio from the microphone. It uses 0% CPU and no noticeable battery use.
Prevents apps from using your microphone.
The all-in-one app for digital and physical security. Learn about the latest risks and how to mitigate them. Designed and used by journalists, aid workers, human rights activists, and people travelling in high-risk areas.
NOT ON THE OFFICIAL REPO ! Umbrella official F-Droid repo
Digital and Physical security advices
With Wassword you can easily generate complex passwords and use them for your online accounts. Choose length and chars to be used and generate your passwords safely.
Password generator if you need one. NOT A PASSWORD MANAGER
Stream music and videos from YouTube Music, with offline cache, background playback, playlist import, and lyrics editing capabilities.
Probably the best free music streaming app that is open source. Accountless
YouTube Music streaming for free
Best material design music player for Android. Metro is a fork of Retro Music with Google Play API removed and all pro features unlocked.
A beautiful, features rich FOSS music player for your Android. It has a lot of customization available.
Worth mentioning :
Pulse Music and
Retro Music Player
Vanilla Music is designed to be simple, clean and minimal. Supports browsing by folder, queueing, shake-to-skip and more.
A nice and lightweight music player with extensions so you can customize what you need
Worth mentioning :
Music Player GO
Minimal material design music Player
Worth mentioning :
Phonograph Music Player and
Vinyl Music Player
HoloPlay is a audio only alternative Youtube app using 
Invidious API. You can add your Invidious token and save music to favoris or create your playlists. Open Source project.
If you just want listening music through
YouTube with privacy in mind) This one is really nice !
Worth mentioning :
MusicPiped
Free cross-platform music client for desktop and mobile enabling manual playback, YouTube streaming, playlist creation, time-synced lyrics, and no ads.
This one didn't work well for me but if you're lucky, you should be able to access
Spotify songs with it.
An offline music player that can stream from YouTube and download songs in the highest possible quality.
SongTube is a new beautiful and fast application made in flutter, it supports YouTube audio and video downloading at any quality, In-App YouTube Browser, audio conversion, Playlists and an Audio tags editor.
THERE IS NO OFFICIAL F-DROID REPO FOR THIS APP!! You can download it from alefvanoon's repo
Basically NewPipe with a more modern interface and also a local music player for Android. Maybe it would wok on your device.
Modern music app for Jellyfin servers offering album downloads, offline listening, configurable storage, cross-navigation, search, and artist recommendations.
NOT ON THE OFFICIAL REPO ! IzzyOnDroid repo
A modern and sleek music player for your
Jellyfin server.
Findroid is a third-party Android application for Jellyfin that provides a native user interface to browse and play movies and series.
A third-party
Private offline photo and video viewer with editing tools, format support, secure locking, EXIF removal, no ads, recycle bin, and material design themes.
A promising foss gallery app with great UI
Simple Gallery is a highly customizable offline gallery. Organize & edit your photos, recover deleted files with the recycle bin, protect & hide files and view a huge variety of different photo & video formats including RAW, SVG and much more.
HAS BEEN PURCHASE BY A ZIPOAPPS WILL NOT BE UPDATED ON F-DROID
My go to as a FOSS Gallery App for any Android device !
Worth mentioning :
LeafPic Revived and
Floral Unmaintained
A safe place for your photos. It stores your photos encrypted on your device and hides them from others.
If you need a locker on some of your pics Photok is my recommandation as a simple to use FOSS Android app.
To be used whenever you are showing off pictures to your phone. Prevents someone seeing what they are not supposed to or doing anything to your phone. Start the app by sharing pictures or videos.
Manage your photo collection with Piwigo Piwigo is open source photo gallery software for the web. Designed for organisations, teams and individuals.
If you need a
Google Photos alternative with cloud sync feature. Piwigo is one of your best option. You can self-host it !
Stingle Photos is a secure photo/video encryption and backup application that provides strong security, privacy, encryption and safely saves your media on cloud storage keeping you safe from data breaches and leaks.
Should be the best overall FOSS Camera App. But don't expect to much from any foss camera apps
Cross-platform, free media player supports multimedia files, DVDs, streaming, offers hardware acceleration, 4K, lossless audio, and more.
Should I present you the cone ?
Versatile media player supporting multiple video formats, wide codec range, subtitles, hardware acceleration, OpenGL output, and intuitive CLI controls.
Some prefer MPV over VLC
Worth mentioning :
Just (Video) Player
NOVA is an open source video player for Android. It consists in a fork of the original 
Archos Video Player Community Edition.
A powerful FOSS player for Android !
Kore™ aims to be a simple, easy to use and beautiful remote that lets you control your Kodi® / XBMC™ media center from your Android™ device.
Remote for Kodi
Remote for Roku
This is a fork of 'Universal TV Remote' by Twinone from 2015 sources. In addition to customizable TV remote, it removes ads, tracking, accounts, uploading, and network access.
Universal InfraRed Remote if your phone supports it. Lacks a ton of device but is worth trying !
A free and open source podcastmanager for Android, allowing you to subscribe to podcasts (via iTunes database & OPML), automatically download episodes using powerful mechanisms and listen to them the way you like (speed, balance adjustments, etc).
The king of FOSS Android podcast app !
Escapepod is a simple and lightweight app for listening to podcasts. It's bare bone approach may not be to everyone's taste: Escapepod is an app of type BYOP ("bring your own podcast"). It does not feature any kind of built-in search option.
Simple and lightweight podcast app.
Introducing Podverse! The easiest way to create and share podcast highlights of any length online. Discover new podcasts by browsing highlights in the app, and send highlights to your friends to introduce them to your favorite shows. No login necessary!
A good looking podcast app.
Worth mentioning :
Tsacdop
You just add your main audiobook folder and every folder in there will be recognised as a single book. That keeps your library simple and tidy.
Listen to your favorites audio books with this FOSS app.
Worth mentioning :
AudioAnchor
Librera Reader is a highly customizable and feature-rich application for reading books in PDF, EPUB, MOBI, DjVu, FB2, TXT, RTF, AZW, AZW3, HTML, CBZ, CBR formats on Android devices.
An ad-free version for f-droid users :)
An ebook reader application supporting PDF, DjVu, EPUB, FB2 and many more formats, running on Kindle, Kobo, PocketBook, Linux and Android devices.
Open-source manga reader for Android 6.0+, featuring over 1000 online sources, offline support, customizable themes, and privacy-focused design.
Just the best manga reader, trust me you won't find better (even on the
Google Play Store )
Worth mentioning :
Kinoko
Android app for downloading novels. Contribute to LagradOst/QuickNovel development by creating an account on GitHub.
NOT ON THE OFFICIAL REPO ! IzzyOnDroid repo
A really nice LightNovel reader
Worth mentioning :
Shosetsu
Comments
Amazing. Can't believe I didn't find this list sooner. My F-Droid client of choice is Droid-ify.
F-Droid is operated by a censorship-prone megalomaniac. Freedom only for special people.
Might be worth adding this: raw.githubusercontent.com/efreak/auto-daily-fdroid/main/fdroid/repo Unofficial repo of Tachiyomi and known forks (SY, AZ, J2K, Neko; also Takoyomi, Sorayami, Aniyomi, Animiru), FastHub Revived, and Hacki (flutter HN client).
Hi, I love the concept of Echo, but it is not maintained, it's buggy and missing many features. Do you know about any alternative? Thanks
No I'm sorry, can't help you on that
Hey it's been a long time but maybe if you still are looking for such an app you could try
Alibi
I have a recommendation for the "Screen addiction" part.
TimeLimit.io can be set up to automatically block certain apps after you use them for a configured amount of time. It is highly customisable. If you don't trust yourself, you can autogenerate a password and give it to a friend or family member so you need to ask for it every time you want to change something.
You should add this app in "Social & communication PART VII - Twitter" section The app Is called harpy https://github.com/robertodoering/harpy
I know Harpy, but do you know if it's on a f-droid repository ? It's not on the official one or the IzzyOnDroid and I couldn't find any repo on their GitHub
You can find this app in one of my other list :
Unfortunately it is not on f-droid or izzyondroid . its only available through play store beta testing and you can download it from github also
I will make a request in their github page to add it to izzy's repo
The dev of harpy quoted this
"There are no plans to bring harpy to f-droid at the moment but if you want to avoid the play store you can download the latest apk here: https://github.com/robertodoering/harpy/releases"
A few more recommendations:
QuickTiles: Add a lot of useful Quick Settings tiles https://f-droid.org/en/packages/com.asdoi.quicktiles/
Forkyz: Crossword puzzles - Guardian cryptic, WSJ, and more, plus support for local puzzle files in a variety of formats https://f-droid.org/en/packages/app.crossword.yourealwaysbe.forkyz/
SimpleReminder: Quickly create reminders and get notified later https://f-droid.org/packages/felixwiemuth.simplereminder/
Easy Noise: Simple white noise app (full disclosure: I made this one) https://f-droid.org/en/packages/com.cliambrown.easynoise/
I'll take thoses in consideration, wanna add many many many more apps but since I have to add them to AlternativeTo it takes some times wich I don't have at the moment ^^'