I'm going to provide a bit of context first, I have a phone called a P6000 (Android 5.0 01), which like some phones, has a detachable battery. I have an extra battery to use while the other charges. Now when I took the battery out of the phone with Fallout Shelter open, upon reopening the app after start up, it would get a couple of seconds beyond the Bethesda logo screen, then kick me out of the app completely. No warning, no crash report, nothing. And this has happened twice. That was the first time, when I had just started. The second time, after I re-installed the app, my vault had 68 Dwellers with happiness averaging at 98%, 150,403 Caps, and enough items for every single Dweller. During the sale of September 3-7, I also purchased 80 Lunchboxes ($40 purchase for the price of $20.) I had to get all of the loot refunded because I can't do anything with that loot, since it wouldn't even let me in.
TL;DR: When past the Bethesda logo, the game crashes. Continuously.
And I can't be the only one with this issue.