A free program for Android, by Aracc Lib.

YMusic: Free YouTube music player is a free music player for playing all popular music on YouTube and other popular sites. YMusic lets you use all the music you want on your mobile device.

YMusic can even let you create playlists and play them. You can add any song on the list and play the playlist or specific songs from your playlist. It’s also possible to change the playlist or delete it completely.

You don’t need to pay a penny for the app to play.