I used the free Wahoo Fitness App until I recently got a Garmin Edge 520. The app was fine, much better than Strava at showing information and also not using as much battery, but the old phone I was using just didn't have enough battery life for the longer rides I plan to do this summer. I like that the Edge is a lot smaller and weatherproof, as my handlebar was too crowded with a ginormous waterproof phone mount in between light, action cam, and tail light remote.