I decided to scratch my own itch as I like to play music via YouTube with friends when we're together and usually this involves switching between two open tabs on YouTube. It was also a nice project to warm up again after a long sabbatical and to try some things I've never played with before (Front-end programming, Responsive design, Hosting static site via AWS).
I've got some ideas on how to improve it if there is interest (to be honest it scratches my own itch so well I'll probably make the improvements anyway :) ).