The Guitar Hero: Live app was removed from App Store on Friday, June 1st 2018 as part of the GH:TV Sunset announcement.
Sadly, the game can no longer be downloaded. If you still had the game downloaded, you would continue to be able to play LIVE and GH:TV modes until the GH:TV Sunset on December 1st, when GH:TV is shut down, leaving LIVE only.
I just bought one of these from Toys R Us only to find out after getting home there is no app. Why are these still being sold if there is no way to play? I can’t even return because the store is closing! What now? What a rip off & waste of money & time. Not to mention how disappointed my daughter is.