See it in action on my YouTube channel: https://youtu.be/53YwF0gJ2_A
iPhone app URL: https://itunes.apple.com/gb/app/hm10-bluetooth-serial/id1030454675?mt=8
Android app URL: https://play.google.com/store/apps/details?id=project.bluetoothterminal&hl=en
Sketch based on this Instructable: https://www.instructables.com/id/WS2812-controlled-with-Bluetooth-and-Arduino/?ALLSTEPS