So I just uploaded the Cycle Tracker app to my Iphone today, looks great for my needs, actually seems to have more wiz bang than I require. Anyway, I noticed if I choose to upgrade the App for the annual fee one of the benefits is purchasing sensors. So I did a Google search and came up with Wahoo Fitness Sensors. My questions, are these any good, any other recommendations for alternatives? What I am interested in is a cadence and heart rate monitor band. Thanks.