Looking at the description, it seems to require purchasing a premium version for the ability to add and modify items on Android, not sure if that's something I would want.

This is true if you download it from Google Play. If you sideload the GitHub APK, you get all premium features for free.

Go for it if ineducable.

Good that it's compatible with Vaultwarden, otherwise a future move from BW would be to block alternative clients like this...

And this is the problem now. Even if BW doesn't plan to do this, we'll always be suffixing that kind of sentence with "doesn't plan to do this.. yet". We've seen this happen too often in the past years, and now we have to consider VC-backed open-source as potentially hostile and prepare for the worst, which means we can't trust them as much...

For anyone else interested: it's licensed as source-available "all rights reserved", not under the usual MIT/GPL licences.