My daughter is into K-pop (Korean pop), and has a BTS (a music group) light stick. Apparently most BTS fans have such a light stick. My daughter even has multip

My daughter is into K-pop (Korean pop), and has a BTS (a music group) light stick. Apparently most BTS fans have such a light stick. My daughter even has multiple versions. It has RGB LEDs inside that are controlled over bluetooth by an app. When you buy a concert ticket through this app, and you bring your light stick to the concert, this app controls your light stick as a pixel in the crowd. It knows your seat number, so it knows where "your pixel" is in the crowd. It can produce some really cool looking animations. https://www.youtube.com/watch?v=vkRKZLUwWkc https://www.youtube.com/watch?v=vkRKZLUwWkc