HealthFit

Apple Watch collects all sorts of exercise data — but that's not a big help if you're already invested in another fitness platform. HealthFit is a simple app that unlocks all these metrics, letting you export .fit files that you can then import into Strava, Garmin Connect, RunKeeper, and others. The files include heart rate, GPS routes, swimming and running cadence, and segments, and can also sync your resting heart rate and heart rate variability data directly, depending on the platform.