Both my iPad Air and my rMini were freezing up after deleting mail from trash after the 8.0.2 update. Restarting would reset it until I cleared the trash cache and it would freeze again. When Gmail was stuck, all other functions and apps work perfectly. To correct the issue I deleted my Gmail account, and did a "hold both buttons" restart. After restarting I added my Gmail account back onto the iPads and all seems OK.