YMusic is a music application developed by Music App. This application lets you play YouTube videos in the background.
A lot of people use YouTube to listen to music but the Android application doesn't let you play videos in the background unless you pay for a Premium account. By installing YMusic, you can bypass this restriction so you can enjoy music no matter what you are doing.
Along with allowing you to play videos in the background, YMusic lets you download any videos on YouTube. You'll then be able to automatically convert it into formats like MP3 so you can listen to any YouTube video on another music player application.
Overall, YMusic doesn't work as well as having a YouTube premium subscription but you won't have to worry about paying monthly just to get a couple of features.