I would’ve said Infinity for… something, but we know how that turned out. So, I’d say it ir most likely Fennec F-Droid, it is the first app I install in every device that isn’t a tablet

BitWarden.

One of the best, if not the best password manager I’ve ever used.

is Tachiyomi open source? if it is, then that. It’s always one of the first things I install on my device.

There’s just no better manga/comic reader app on Android (even on PC tbh).

The only thing better than Tachiyomi is one of its forks like TachiyomiSY which I’m currently using.