The ultimate F-Droid setup (WiP 150+ Apps)

This is the official f-droid client ! The UI is a bit old comparing to new standard but it is not ugly either. The UX is not that great as it can't recommend you apps and the search is quite terrible. However it's the stock store on CalyxOS and GrapheneOS so it comes with installation privilege and let you install apps in the background. So if your OS comes with the official client by default I recommend you to stay with this one. However if you want a different experience here are the third party client I recommend you to try.

G-Droid has a simple classic material design UI but comes with a better UX (just a bit) than the official client. It is quite popular in the F-Droid community. You can't go wrong with it

Another classic material design UI but that is looking more modern. This client is quite new but is worth looking at.

A really nice client from the devs behind the quite popular Aurora Store . The UI is really modern looking and you can add custom repo at the initial setup which is really nice. Some users seems to experience bugs here and there.

If you like old UI style or you're an OG with a hate for change this is your client to go !

Worth mentioning : F-Droid Classic

This one is not just a simple F-Droid client it's a complete new of a kind decentralized app store for Android that can sync with the official F-Droid repo.

Koler is a uniquely stylized phone app for Android, designed with the user in mind.

A simple dialer app from Simple Mobile Tools

The king of SMS apps (even better than stock non FOSS ones)

Worth mentioning :
Signal if you are already using it you can set it as default SMS apps and send SMS by long pressing the blue send button to turn it gray. There is no official f-droid repo !!!

Simple SMS Messenger

THERE IS NO OFFICIAL F-DROID REPO FOR THIS APP!!
You can download the de-googled version from the CalyxOS repo https://github.com/CalyxOS/calyx-fdroid-repo

The best simple to use and complete encrypted messaging app for everyone (except those who wants anonymity !

Worth mentioning : Molly (Signal fork) An independent fork of Signal which let you communicate with Signal users that adds extra-security features. Comes in two flavors like Signal one depending on GoogleMobileServices for notification and one who is independent.

Completely different FOSS messaging apps from the official f-droid repo but also worth mentioning :
Status
aTox
Telegram FOSS ( NOTE THAT CONVERSATIONS AREN'T ENCRYTED BY DEFAULT!!!)

NOT ON THE OFFICIAL REPO !
Session official F-Droid repo > https://fdroid.getsession.org/

A decentralised Signal fork that is more private and does not required your phone number so it can be used anonymously ! It also anonymised the traffic !
It is (yet) not as polished as Signal !

CAN'T BE USED WITH Signal USERS !

Probably the most secure and private decentralised messaging app.
Route all traffic through the Tor network to keep you anonymous. Can send message through bluetooth.
Has very limited functionalities (yet) for a messaging apps and is only available for Android users !

Element is a Matrix-based end-to-end encrypted (E2EE) secure collaboration and messaging app.
It provides instant messaging, voice and video calls, screen sharing and file sharing; for 1:1s to huge chat rooms. It’s available to use across Web, Android, iOS, macOS, Windows & Linux.
Its decentralised design delivers digital sovereignty, enabling deployment on-premise or through any cloud provider.

The OG FOSS Facebook client

A more lightweight FOSS facebook client ( < 1 Mb )

The purpose of this application is to get access to Facebook events without an account.
Therefore it does not use the Facebook API.
Instead it opens the Facebook event URI and downloads the website HTML code.
This source should contain the event information in form of structured data.
That data is extracted and used to create Android events.

Features:

• Does not use Facebook API
• Supports "open-with" and "share-to"
• Independent from Facebook regional sub-domain URLs
• Saves history of scraped events
• Handles upcoming events from pages

A decentralised privacy-friendly Facebook alternative.

Worth mentioning : Fedilab Also a client for other decentralised social network

THIS APP IS DISCONTINUED DUE TO META (FACEBOOK) RESTRICTED POLICY FOR THEIR DATA COLLECTING MONOPOLY !
Having the PWA (Progressive Web Apps) in a sandboxed browser could be a better alternative. Do your own researches !
Suggestion : WebApps

If you just want to see some Instagram content but don't want a Meta (aka Facebook) app to spy on your phone just use barinsta.
It's customizable and is more oriented in a detox use of instagram instead of endless scrolling and double-tapping sessions.
You can use it without logging in but sometimes Facebook will temporarily bans your IP so sadly it's recommended to be logged in...

PixelDroid is a Free and Open Source Android client for Pixelfed , the federated image sharing platform.
Browse feeds and profiles, upload new posts, discover posts, interact with others on the fediverse.