How to transfer all workouts from Endomondo to Strava and vice versa?

Let’s say you’ve been using Endomondo for few years and you want to move to Strava with all your activities. If you export each workout’s gpx file and import it to Strava, it will take ages. Especially if you have tons of workouts (I bet you do).

This situation happened to me last month, when I realised that Strava beats Endomondo in all aspects.

The  best solution I found to sync between Endomondo-Strava-Garmin Connect activities including all data was http://www.tapiriik.com