I started with the free version of this application, before moving to the purchase version. I use it for a very specific purpose: practicing scales on a musical instrument. It allows me to set the time spent on each scale, the duration of the rest between each scale, and how many times I would like to loop through the complete set of scales. The application is highly configurable, and allows the following features, that I find useful: incoming text messages will appear briefly on the top of the screen, the application allows one to turn off the auto lock feature, and the durations and sounds are all highly configurable. It is a terribly useful application, and I use it daily. Bravo.