I'm trying to get some pictures onto my Android phone with >8bpp depth and without the large file sizes of png and the like.

Android 12 supports avif, and that's great: https://developer.android.com/about/versions/12/features

I'm using a Samsung phone with Android 13, that sounds great too concerning avif support. Unfortunately it doesn't seem to work, only web browsers and the basic, dedicated app "AVIF Viewer" are able to open the .avif files - every other viewer app, Samsung built-in or external, doesn't.

Alas, avif support seems to be on the same level as jpeg-xl (works in browsers and one dedicated app). 12-bit legacy jpeg doesn't seem to be supported either.

=> Has anyone managed to find a viewer app with browsing feature (swipe to change pictures) that supports avif, or to convince Samsung's built-in apps to display .avif files?