My favorite thing about desktop version of foobar are its metadata capabilities. And it does not exist in mobile version of foobar or is so counterintuitive that I still haven't figured out how to do this.
What I would expect from foobar mobile in regards of metadata:
- presence of "Metadata" or "Properties" command. Where? First of all under these 3 dots in low righthand corner in Playback Controls view. Again, you should learn from Sony's "Music" app. In its "3 dots" menu located at top righthand corner there is entry for editing metadata. Then you should go beyond "Music" and it should be also available as long-press option when viewing music in Media Library view. On the other hand "Decoding speed test" present there now is most useless option I could imagine...
- presence of "Download metadata" option in metadata editor. While Sony uses Gracenote, foobar can use freedb for the same purpose (or anything else which would fit).