A few months ago, Ghost Trick: Phantom Detective was removed from sale on Apple's App Store due to compatibility issues with iOS9. That in itself didn't make a whole lot of waves, but then last month it was removed completely, meaning people who had already purchased it weren't able to download it again. Yikes.
All is now well again for the realm of specter tomfoolery. Ghost Trick is now back up on iTunes, fully compatible with the latest iOS devices. You should check it out if you have the means. It's pretty dang good, and the first couple chapters are free.