I have used this is my classroom for three years. It works like a charm. The students love to see how many gum balls they can earn during the given time. I have either set the timer for the full amount of work time or set it for smaller increments of time. As a reward, if they reach the goal, I sometimes give a piece of bubble gum, or something toward a classroom goal for some other reward...For example I might give them a letter toward building the word Compliments.
Classroom Timer Pro - The engaging graphics and sound effects mean tasks get completed in a fun and efficient way. The teacher sets the target amount of time for the class to perform a particular task. The countdown timer is then started. The timer can be viewed from the Apple device itself or displayed on a larger format device such as an interactive board or TV screen using screen mirroring features of the Apple Devices.