I switched from Mint.com to the FOSS Money Manager EX for desktop a while ago and couldn't be happier.

I use DokuWiki for my personal wiki. Very easy to use.

Immich is the must for self-hosting photos. Bye Google.

I use the Unison file sync tool to keep backups of all my important files on flash drives and servers. For mobile devices I do use Syncthing because MTP is painfully slow and taking the SD card out of the device to plug it in is too much of a hassle, but I would rather use Unison.

Android

Audile like SoundHoud and Shazam but open source

Funkwhale a federated cloud community music streamer app

Innertune find new songs from YT Music

Open Video Editor edit videos

Heliboard successor of OpenBoard

Tubular successor of NewPipe

ZipXtract a zip extractor

Wger fitness app

Please just a reminder, consider contributing to these apps developers.

Grisbi, for finances.

Next cloud and only office. Bye bye google drive

Jellyfin bye bye Plex and Netflix

Paperless has taken me from various stacks of important documents strewn around my apartment, to having all of these things nicely organised and searchable.

LogSec for students, project organization, and the aspiring corkboard conspiracy theorist in your life wanting to be the next Mark Lombardi. Use markdown in a free flow style notes app that has powerful tools to connect ideas, so you can focus on the information as opposed the organization. Semantics instead of syntax, as it were.

SC-Controller, although it seems to have been abandoned.

Gpodder-adaptive