This App is free and it works on the iPhone, iPad and iPod Touch. You select a goal and level, then find a workout that meets your criteria. It's rewards based, so you get to see how your latest workout has brought you closer to your next reward, like power smoothie recipes or high energy training circuits. I can't wait to use this tool next time I am at the gym (or not!).
I have already mentioned this app offhandedly when I did my year end summary, but I thought it was worth re-mentioning. There are three things I like about this app. One, the ambient sounds are varied, although I doubt I will ever get sick of listening to a mountain stream as I fall asleep, since camping in the Gila Mountains by a stream is my "happy place." Two, There is a guided sleep meditation, which helps with my goal of meditating more this year. Three, there is an option to add a layer of binaural beats, and I have found this to be très helpful as a relaxing white noise option.