This website is a tool for building Spotify playlists for dance events. Rearranging track order, for example, is cumbersome to do in Spotify, as is inserting special sound effects or silence every second or third song. The website greatly simplifies those tasks by providing drag-and-dropping, automatic track insertion, track selection, and randomization. Moreover, it also provides BPM and genre tagging per song.
Note that this website relies heavily on click-and-drag and right-clicking, meaning it will not work as intended when viewed on a phone.