to name a few I like:

• Read You, brilliant RSS reader. Now syncs with Freshrss. Inspired by Reeder on iOS
• Voice, audiobook player. I use it in fact to listen to audio from youtube videos (downloaded with Newpipe). For audiobooks (and podcasts) I use
• Audiobookshelf (needs server)
• FUTO keyboard with decent on device voice recognition! (exists as a standalone)
• 8Vim, weird keyboard I really like
• Fairemail has been my trusty email client for years. Don’t be spooked by its many options, once accounts configured the UI doesnt show unecessary stuff IMO. Some unique and useful features.
  But if you want something simpler there’s K9, now Thunderbird. Although I still experience the issue with emails not arriving on time with this newer version
• KeepassDX, great password manager, good UI, keeps improving.

Thunderbird, Firefox, Element, Home Assistant, DAVx5, AntennaPod, Immich, NewPipe, Task.org, SyncThing, Tusky.

• Seal: Allows me to download YouTube videos, Instagram reels, etc. It’s a simple and pretty front end for yt-dlp.
• Fossify Calendar: Finally kicked Google Calendar to the curb. No fuss calendar app.
• AVNC: Allows me to remotely control my laptop from my phone. Requires installation of VNC software on the laptop (I’m using TightVNC).
• Binary Eye: Barcode/QR code scanner with history.
• Loop Habit Tracker: Helps me keep track of habits – eg. going to the gym X times a week.
• Island: Allows me to create a clone of app. Useful for apps that don’t support multi-accounts.
• Simple Time Tracker: I use it to keep track of how long I spend playing a game, since I like documenting the info for HowLongToBeat.com

Other than these, K9 Mail and NewPipe.