Vibration before commanding
you are sending your troops to get a fort. It's a long way, let's say 1 hour. You are putting your phone away and start watching a movie in TV. You're losing a track of time and when you take your phone back to hand, the battle is over. You forgot to command and lost some troops.
My suggestion is to add a vibration signal or beep beep, when there's one minute to start commanding your troops.