Zarlin

The systemd website itself seems quite information-rich: https://systemd.io/

This is the currently maintained android version: https://github.com/researchxxl/syncthing-android

Since she likes puzzles, the Trine game series could be nice! I think they added coop multiplayer starting with Trine 2.

If you both like hack 'n slash then Torchlight 2 is also great fun!

Take a look at Bunny ( https://bunny.net/dns/ ), they’re based in Europe with worldwide coverage, and have a lot of other useful services as well.