Confirmation in tech-upgrade.
recentry i had trouble with tech upgrade that tapping on screen caused double tap registered inside the game software which caused unwanted upgrade of tech
. i have sent suggenstion about add confirmation. anyway today, just now, i had same trouble again and my tech-digging is getting upgraded again, which i really do not wannted because stones are always over flown in warehouse. have sent letter to support immidiate and thir answer is that i can not cancel the upgrade. now this is very bad. i think tech-upgrade should be done same way as other upgrades. 

