I am currently playing "It takes two" together with my wife. It looks cute, has a story that is funny and really sad at the same time and the mechanics of the game change frequently. The occasional (optional) Minigames are really fun too!
While Keepass has the ability to use a Yubikey (or similar) as 2FA (masterpassword is still required), this does not work on the mobile (Android) apps I tried. If you can make it work, please let me know!
Other than that: I got my Yubikey working ok on Linux Mint. But somehow the first login often does not work as expected (you have to touch the key). That is why I don't use it anymore as 2FA for computer login.
Mostly covers for different hoses and valves for scientific instruments used underwater. For the seals I mostly use O-rings.