Countdown timers in Planner...

I've scoured the web and cannot find an app that does this: set up a series of countdown timers for the day's tasks.  As the lesson progresses, the teacher selects the next task from the list to start the timer. Lots of countdown timers in the app store, but none do this. 

Ideally, I'd be able to do this right in the Planner section of idoceo, where I already have detailed lesson plans. If I could simply assign a countdown timer to each item in the lesson plan, and then select/start/stop the timers from a floating-pallet list of tasks.... 

A simpler approach would be to have a floating pallet with a dropdown menu of times. Teachers could add to the list. There are apps that do this (not easily), but it would be nicer (and easier) to have this function integrated into idoceo.

Any thoughts?

P.S. I discovered the Timedrop timer last month. Intriguing features, but if I leave the page, then return, the timer is no longer there. As a result, I cannot use it for the above purpose. Be nice to have it on a persistent floating pallet.

Hello  pauhana658 .,
 Have you tried the Timer 1 and Timer 2 as a widget in the Summary? 
 It keeps the timing even if you switch classes

Yes, I did try it, but the timer stopped when I left the Summary page and then came back. A bug? Or is there something I missed in setting up the widget?