>>95976913
It could work. The player before you end his turns and pushes his turn button. It's your turn and your time is running. When someone wants to react during your turn, they push their reaction button and their time is running. When they are done reacting they push that button again and it's your time.
People would have to constantly smash buttons on a phone or tablet and it's easy to mess up. But it would work with the priority system.