Everyone knows it, you're at the gym and don't know exactly what to do, or you're not quite sure anymore how to perform the exercise and what to watch out for in doing so. You type something online and you get a video. It starts with 2 interruptions, after which someone is talking for 4 minutes. When he/she just wants to show you the exercise, 2 more interruptions pop up first. So we experienced this problem as well. For this we designed an app with short but very powerful videos.