Currently in Beta! Please register interest at https://eflip.me/
This app is an electronic music viewer/electronic flip folder and group performance manager. You set up a musical group at eflip.me, upload music to an online cloud like Box or Google Drive, and then give other members of your group a "Connect ID". Members of your group are able to connect to your band using that ID and then view the music you upload.
You can also define band leaders who are able to start and end performances. Performances are the key feature of this app. Whenever a band leader selects a song in the performance manager, that song will pop up on all of the individual player's devices as long as they haven't left the performance and have some form of internet connection. It will also pre-download all of the songs so during a performance there is no heavy lifting required.