This app was mentioned in 3 comments, with an average of 1.67 upvotes
Fun Fit is just HTC's own fitness app. Most fitness trackers have not worked on the M8, which I know has to do with the 'smart sensor hub' thing they did, just hoping that they got rid of that atrocity in the M9 and HTC 10
https://play.google.com/store/apps/details?id=com.aiqidi.nemo but I'm guessing you shouldve installed before