What phone/tablet model are you using?
Ipad 2
What OS are you currently running (including version #)
iOS 7 and 8 (8.3)
Did you delete the game and reinstall it, or just update over the old build?
If you updated, did you manually update it, or allow the store to auto-update it?
Game was up to date as of today 10/27/2015 via auto update.
As of today the game was absolutely unplayable, right as the vault loaded and dwellers were coming back, the game would lock up and crash. I tried letting it sit / not tapping anything, I tried hurrying up and tapping resources before it locked up, nothing worked the game always locked up. This was on iOS7 (iPad 2) and I've been putting off the update to iOS8 so I figured might as well try the game doesn't work as it is anyhow. Updated the iPad to the latest iOS version (8.3) fired up fallout shelter - exact same results.
So at this point I made the terrible mistake and uninstalled the game and reinstalled it when prompted to remove or keep game center data I chose KEEP. Game works now but I lost EVERYTHING 5 Mr. Handy's and 40 lunchboxes. What a complete and utter waste of time and money (yeah I was foolish enough to support this game with a $10 purchase). From what I read elsewhere I'm pretty much f'd.