I do not want to try all those players available out there one by one. With a MP3 (or media) player) I would prefer open source.
The built-in player in FP Open OS looks like it could support album covers, but even if the cover is avaible as JPEG or PNG inside the album folder, it is not displayed, just always the same default image. Does the player expect some special format or a special file name (other than cover.jpg)? Or is it necessary to create a playlist for that?
On the desktop I use Banshee. I do not expect (or need) all the functions of Banshee on the smartphone, but sorting and searching would be nice. And cover art…