Noxious

Or Tmate if you use Vim (or another CLI editor, or basically anything in the Terminal)

Immich is funded by FUTO btw

Why?

It’s impressive how many things can be achieved with nothing more than the power of open source software

Rclone with crypt seems pretty nice

The new Element X is written in Rust and thus memory-safe. SchildiChat Next is based on it.

Fluffychat and Syphon are pretty good

Yes

Finding anything FOSS with Spotify integration will be basically impossible. Clock You is a great clock/alarm app in general, of course no Spotify integration though. But you can choose custom music you have downloaded on your device.

OSS Document Scanner is great. It’s also available in the IzzyOnDroid F-Droid repository: https://apt.izzysoft.de/fdroid/index/apk/com.akylas.documentscanner

Yes, I know, draw.io theoretically isn’t entirely open source, but the source code is available and it can be self-hosted. Honestly, that’s good enough for me, I think I can make an exception for this one. But generally I care a lot about strictly using FOSS too. It can also be integrated with Nextcloud: https://apps.nextcloud.com/apps/drawio

Frigate is pretty nice. If you need a simpler setup, go with Rpisurv, it’s made for a Raspberry Pi, and very easy to setup and use.