Item description:

tangerine is a work-in-progress music player for the Nintendo 3DS and Nintendo Switch.

Features
Support for multiple formats (wav, flac, and mp3 currently).
Ability to play playlists.
Anything else the 3DS's sound application does.
Touchscreen controls.
Building
You can just run make or make all to get both 3ds and switch builds, but for just one of them follow this:

3DS
Make sure you have the latest releases of ctrulib, citro3d, citro2d, and 3ds-mpg123 installed via the devkitPro pacman.
Then type make 3ds to get a .3dsx, .smdh, and .cia.

User guide
Put all music in /music/ folder on your SD card as traditional file browsing is not currently supported yet.

Controls
L/R - Skip forward/back a song

A - Pause/play

B - Return to file selection

Progress bar (touch screen) - Scrub through the audio (slow)

Known issues
Some flac files have issues with playback speed on hardware but work fine in Citra.

Scrubbing within flac/mp3 files may take several seconds on Old 3DS depending on the size of the file