The app pretty much meets my needs. You can always question the accuracy of calories burned but I use this app more to provide the beat for my running. As I use an Elliptigo bike on a stationary trainer, its also great for that, as well! Just review any music you use other than the built-in app music. The app does not do a very good job of getting the BPM for the music right. For every 5 songs, the BPM for 1 of the 5 is correct; 2 songs are +/- 1 BPM & the other 2 are completely wrong. Considering that the app will increase or decrease the BPM, a 1 or 2 BPM inaccuracy can be significant. Fortunately, you can change the BPM for any song you include in the app. Thats why I only gave it 4 stars. Trying to correct the BPM for the 55 songs I uploaded to the app was quite a chore.