If you can't play perticular formats this could be. RetroMusic uses the native media player that comes with your phone, so as long as a filetype is supported by your phone, it is supported by RetroMusicApp.

Opt-in for beta build https://play.google.com/apps/testing/code.name.monkey.retromusic

Download latest beta version

We're active in discord if your using one join https://discord.gg/qTecXXn

- Icon set changed to match with fully Material Design guidelines
- Now, most of the dialogs are Bottom sheets
- New album & Tag editor UI
- New Icons set(smooth style)
- New app icon(Experimental)

-fixed save playlist
-fixed tiny theme size consistency
-fixed plain theme titles padding
-removed gradient progress in mini-player
-fixed playlist details status bar colour (when base colour theme selected)
-improved album and artist details page UI
-new material theme(free)
-fixed slider black dots full and blur theme

-added album and artist grid style chooser
-fixed material theme artist name color
-fixed crashing home screen on tablet
-removed gradient in material theme
-fixed sleep timer text color
-fixed blur theme landscape mode

Do you like card style for album and artist list
public poll

Yes – 488
👍👍👍👍👍👍👍 91%

No – 47
👍 9%

👥 535 people voted so far.

-added artist image to album details page
-fixed crashing for tablets
-fixed fab color for normal theme
-fixed dialog theme now follows app theme
-added suggestions loads other albums from same artist name in album details

Change log window

Changelog window on every update
public poll

Yes – 704
👍👍👍👍👍👍👍 96%

No – 26
▫️ 4%

👥 730 people voted so far.

Do you use Tabler/ Pc/ Big screen to play song
public poll

No – 433
👍👍👍👍👍👍👍 65%

Yes – 238
👍👍👍👍 35%

👥 671 people voted so far.

Do you use wearable
public poll

No – 423
👍👍👍👍👍👍👍 75%

Yes – 141
👍👍 25%

👥 564 people voted so far.

There's a limited amount of requests the app can make to the last.fm servers for these images. If you're out of luck, you have to wait until next month.