DJI's Spark drone starts recording when you raise your arm
 

When we reviewed DJI's Spark drone, one of our gripes was the limited set of gesture controls. You can't do everything you want without reaching for your phone. DJI is already taking steps to close those gaps, though. It's delivering a firmware updat...

https://www.engadget.com/2017/08/02/...ding-gestures/