Here’s mine:

• AnkiDroid - mobile version of popular desktop flashcards software Anki
• Bitwarden (don’t remember if this needed a repo) - favourite password manager
• Catima - holds loyalty cards
• Fennec F-Droid - Build of Firefox without ads and that supports more extensions
• DiskUsage - see what’s taking up your disk
• GadgetBridge - FOSS app for smart watches, Mi bands etc.
• Lawnchair - Home screen replacement that’s visually identical to the default one but allows me to double tap to lock
• Material Files - file manager
• Loop - Habit tracker
• p!n - Pin reminders to notifications
• muPDF Reader - fast PDF reader that doesn’t crap out when I zoom in and out unlike Google Drive
• Simple Gallery - lightweight gallery app
• NextCloud and NextCloud Notes - Access NextCloud
• Scrambled EXIF - Share pictures without giving away EXIF data
• Tusky - nice Mastodon client
• Shattered Pixel Dungeon - a game way too addictive to be safe to install
• NewPipe - FOSS frontend with AdBlock and downloader for YouTube, SoundCloud, Bandcamp and others
• Librera - read EPUBs
• Lemoroid - Nice libretro client to play video games
• Infinity - Reddit client that still works. I believe they did something hacky with the API key to get around the block.
• Migraine Log - Nice app for migraine sufferers to log their attacks
• Scarlet - Beautiful notes app