I was playing Story Mode and finished a battle which resulted in a new Story Cache.
I opened the cache, salvaged an item and put my phone down for bit. When I came back and unlocked my phone the game was unresponsive.
I closed it and opened it again.
Every time I open the game it replays my last turn and shows me winning the battle and prompts me to open the cache again to continue. At which point the game is unresponsive again.