I use MapMyRide with an iPhone 6 and itnwould spike from time to time. I recently purchased a Wahoo Blue SC and my speed and distance are rock solid now. It also gives candence. I actually purchased the Wahoo RFLKT along with a Wahoo Tickr HRM. It has been the best investment in terms of loggin data and seeing instant speed. Highly recommended and no more innacurate data.