Almost all of us at some point have lost gems accidentally. I myself lost 400 gems when my 5 year old cousin bought Gold from them. Now I think Supercell can do a small thing to avoid these.
There should be a 3 digit PIN kind of a thing that every player should be given, whenever A person wants to spend more than 20 gems he should be asked to type the 3digit PIN.
Everybody is smart enough to remember a 3 digit PIN, but if someone forgets it he can see it by going in Settings, his pin should be written there so he can see when he forgets. It will not take more than 5 seconds for someone to type his/her PIN.
Note: Every person's PIN is not needed to be unique as it is just to avoid accidental key presses.




