Like there is the Official Mastodon app for Mastodon, and Element app for Matrix, which app is considered the most official lemmy app for Android [possibly also for ios]
Or atleast, the app which supports most(if not all) the features available in Lemmy
none of them.
i’ve heard that jerboa is from the same devs as lemmy, if that is ‘official’ for you.
i personally use sync, but just because i’ve used it for reddit and i like the interface.