Five years back, YouTube didn't have the feature to queue your videos on the fly. You could have created a playlist, but then it is the same sequence of songs every time. So I hacked a chrome extension to add/remove songs to a dynamic queue saved on your LocalStorage[1]. Later, YouTube added the queue feature. Sometimes I go on long hikes and think that it wasn't merely a coincidence. :)
[1]: https://github.com/nishnik/Play_Next