8 Apps That'll Make High School A Little Easier - check out time management app! I think if you're going to teach high school or raise students in high school then this is a great tool to look at to prepare the kiddos!
Animated timers that you can put on the projector. Gives students a visual for the time they have remaining. Plus a fun surprise (noise cue) when time is up! :) Sometimes kids just need the visual rather than a timer on a desk.