Does anyone use a fitness tracker, like a FitBit or a Jawbone?

While browsing this morning, I've come across a bunch of options, including discontinued models and also knockoff versions. All I need it for is calorie burn tracking. I am doing HIIT spinning workouts at home and I don't have a fitness monitor on my spin bike, so I was thinking I could get one of those fitness bands.

Ideas for me? Thanks!