The new MobileTrack feature uses the M7 coprocessor in recent iOS devices to track movement. I used the app for about a week, but eventually went back to using Pedometer++. Although the Fitbit icon is infinitely nicer than Pedometer++’s, the Fitbit app takes a few seconds longer than Pedometer++ to update my current steps and I liked that Pedometer++ displays my step count with much larger text than Fitbit does.