Dont Upgrade!!!
If you have the free version of IntervalTimer and are considering upgrading, dont! The pro version is not an upgrade, its a new standalone app. Therefore if you have saved routines in the free version they will not be accessible in the pro version. You will have to reenter all your routines. This is a serious flaw, and the developer apparently does not understand the definition of upgrade.
MackyMoto about
Interval Timer Pro