I'm messing around with obtainium and I like it so far. But mobile github is a bit of a pain to navigate. How do you find foss apps that aren't on f-droid yet?
I don't search on GitHub. I find something people mention online or whatever means, then find it hasn't been published on fdroid for whatever reason, then I use obtainium. It's rare I actually need it.
Same, since I got my pixel 7 which seems 64bit app only (unless I missunderstood something) I occasionally run into a problem that f-droid somehow does not supply a 64bit apk. Then I just use obtainium instead.
Also use obtainium for Techmino, because its awesome tetris!
You mean like arm64? You shouldn't run into that issue on fdroid, all modern androids support the same arm64 format, and the pixel 7 definitely does. So that shouldn't be an issue, there is no other format it could possibly be installing that it'd be incompatible with. I've had that glitch sometimes with fdroid, I'd have to cancel the install of an app and close it and it'd usually work. Or an issue in fdroids end.
github actually has a pretty decent tags system, so searching say, "topic gallery + language kotlin" will be a good way to find android gallery apps, or "topic music + lang flutter" can help find cross platform music apps etc