Hi HN, we just released an Android App that is able to measure and react to strikes thrown at a punching bag.<p>Check out <a href="https://punchlab.net" rel="nofollow">https://punchlab.net</a><p>It uses data coming from the smartphone's own sensors and analyzes the signal to detect and measure punches.<p>The App is bag-agnostic and it's able to be accurate enough to track also the fastest athletes (check out this video with a Pro fighter giving up to 7 punches per seconds: <a href="https://www.youtube.com/watch?v=nwaHmgj45aQ" rel="nofollow">https://www.youtube.com/watch?v=nwaHmgj45aQ</a> )<p>let me know what do you think about it, there are many features we are working on!