Liftoff is rather nice

Voyager for lemmy

Liftoff and Thunder

Not sure how many of these are open-source but it's a good start

https://github.com/dbeley/awesome-lemmy#mobile-apps

You can also "install" the mobile web version as an app. Just go to your home instance lemmy.one and and fromthe menu on your phone's browser, there's usually an install button.

This also works for Voyager, https://vger.app/posts/lemmy.one/all

Connect is a good one. It's available for download on Google Play.

I've tried Liftoff (fork of Lemmur that is actually maintained and pretty great) and Thunder as well as Jeroba and Lemmur, they're both better.

Thunder is very iOS-esque and plain, Liftoff has the weird bottom layout Lemmur does, and inherits some strange UX quirks from it such as not storing last sorting preference, not having "block community" in the hamburger menu for posts, and sorting replies by "hot". Itst actively maintained so I'm sure it will improve, and it's the most stable and useful mobile Lemmy client I've tried so far.

I have not tried any closed source clients and will not do so.

The most polished native Android app is Thunder imo. If you are ok with PWAs, then Voyager is currently even better than Thunder

Just a silly thought here, are you by any chance using a service like NextDNS? I couldn’t access lemmy.world because it was blocking domains newer than 1 month old, once I disabled it everything was ok.