When it comes to MP3 players, there is definitely no shortage, but finding a good one is a task
Here are the most popular one, each with it’s advantages and disadvantages
Retro Music Player
Open source: github
Available on google play and F-Droid
Elegant, plays music files and does not do much more
Appears to be written in Kotlin
Fossify Music Player
Open Source: Github
Available on Google Play and F-Droid
Elegant, plays music files and does not do much more
Appears to be written in Kotlin