AdAway for Android via fDroid
Free and Open Source Software
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I have lawnchair and the Papirus icons and I also have some of the Simple App suite to replace the propietary file manager, camera, etc.
I also have a reminders app called Habits, as well as Revanced, Infinity for Reddit (RIP), and Jerboa.
And for games I have Lichess, Mindustry and Shattered Pixel Dungeon
Oooh, Habits is great! I've been looking for a simple habit tracker for years!
Voice for audiobooks, Geometric Weather, Tachiyomi, Feeder for RSS, DCSS & Shattered Pixel Dungeon. All FOSS and all very good.
Nextcloud Notes for notes
Revanced for YouTube, Audacity, KDENlive, VLC, OBS studio, and the *ARR suite of applications.
Edit: I did not see that you said Android. Revanced it is then.
vlc has an android app too! try it out !
Revanced isn't open source. the patches are, but the base client is closed.
Simple Gallery (and the Simple Mobile apps in general), AdAway, SDMaid, Magisk, Firefox.