I like my iPhone screen on over my entire rides, so I hung a small battery pack of the handlebar.
Strava does a nice auto-stop & start, but, of course, one needs to hit the start button when you push off.
Many people forget to hit the stop button at ride's end, pile their bike in the vehicle, and drive off.
Easy to crop out the excess, but many wait until somebody flags their 40mph avg ride!