Just realized this might be useful to other people as well, so posted a new topic with it

siggy47

In short everything from https://f-droid.org is good!

sahil

Aegis Authenticator is a free, secure and open source app for Android to manage your 2-step verification tokens for your online services.

AntennaPod is a podcast player that is completely open. The app is open-source and you can subscribe to any RSS feed. AntennaPod is built by volunteers without commercial interest, so it respects your privacy while giving you full control.

A simple calendar with events, tasks, customizable colors, widgets and no ads.

A Loyalty Card & Ticket Manager for Android

Easy and quick contact management with no ads, handles groups and favorites too.

Sync your contacts, calendars and tasks. Get live-access to your WebDAV Cloud files. All-in-one CalDAV/CardDAV/WebDAV solution for Android

Fully featured, privacy oriented email app for Android

An open-source keyboard for Android which respects your privacy. Currently in early-beta.

A premium app for managing and editing your photos, videos, GIFs without ads

Loop Habit Tracker, a mobile app for creating and maintaining long-term positive habits

Enabling communication between all your devices. Made for people like you.

OpenKeychain helps you communicate more privately and securely.

Organic Maps is a free Android & iOS offline maps app for travelers, tourists, hikers, and cyclists based on top of crowd-sourced OpenStreetMap data.

RHVoice is a free and open-source multilingual speech synthesizer.

A material designed music player for Android

Open source lightning wallets with on-chain support

tech

What else are you an 'early adopter' of?

birdeye21

Here are some useful applications:

[Aegis](https://getaegis.app/).

> Aegis Authenticator is a free, secure and open source app for Android to manage your 2-step verification tokens for your online services. 

[AntennaPod](https://antennapod.org/)

> AntennaPod is a podcast player that is completely open. The app is open-source and you can subscribe to any RSS feed. AntennaPod is built by volunteers without commercial interest, so it respects your privacy while giving you full control.

[Simple Calendar Pro](https://github.com/SimpleMobileTools/Simple-Calendar)

> A simple calendar with events, tasks, customizable colors, widgets and no ads. 

[Catima](https://catima.app/)

> A Loyalty Card & Ticket Manager for Android

[Simple Contacts Pro](https://github.com/SimpleMobileTools/Simple-Contacts)

>  Easy and quick contact management with no ads, handles groups and favorites too.

[DAVx5](https://www.davx5.com/)

> Sync your contacts, calendars and tasks. Get live-access to your WebDAV Cloud files. All-in-one CalDAV/CardDAV/WebDAV solution for Android

[FairEmail](https://email.faircode.eu/)

> Fully featured, privacy oriented email app for Android

[Florisboard](https://github.com/florisboard/florisboard)

>  An open-source keyboard for Android which respects your privacy. Currently in early-beta. 

[Simple Gallery Pro](https://github.com/SimpleMobileTools/Simple-Gallery)

>  A premium app for managing and editing your photos, videos, GIFs without ads 

[Loop Habits Tracker](https://github.com/iSoron/uhabits)

>  Loop Habit Tracker, a mobile app for creating and maintaining long-term positive habits 

[KDE Connect](https://kdeconnect.kde.org/)

>  Enabling communication between all your devices. Made for people like you. 

[OpenKeyChain](https://www.openkeychain.org/)

> OpenKeychain helps you communicate more privately and securely.

[Organic Maps](https://organicmaps.app/)

> Organic Maps is a free Android & iOS offline maps app for travelers, tourists, hikers, and cyclists based on top of crowd-sourced OpenStreetMap data.

[RHVoice](https://rhvoice.org/)

> RHVoice is a free and open-source multilingual speech synthesizer.

[RunnerUp](https://github.com/jonasoreland/runnerup)

>  A open source run tracker 

[Vynil](https://github.com/VinylMusicPlayer/VinylMusicPlayer)

>  A material designed music player for Android 

[Voice](https://github.com/PaulWoitaschek/Voice)

>  Minimalistic audiobook player 

[Geometric Weather](https://github.com/WangDaYeeeeee/GeometricWeather)

>  A Material Design Weather Application 

And of course, [Open source lightning wallets with on-chain support](https://stacker.news/items/222381)