A:Answer I don't have the cellular one, but the Sleep++ app is great. It breaks down restful, restless, and awake for the entire sleep cycle and charts it with easy to understand graphs. I've found it to be 90+ dead on to when I have to bathroom at night or thunder wakes me and when I wake unrested, it shows every time that I didn't sleep well and gives totals too. The graph shows all the events most of the time. It is pretty accurate to when I go to bed but can't fall asleep and knows when I wake very well. There are many more apps for the watch as well which I feel make it worth the money if you have an iPhone already.