the plan is to develop on top of the Mopidy javascript library.
it will be great to integrate the LED matrix APIs so a user could draw on it directly from the same web-interface (or maybe the we could get more ambitious and allow the user to assign an emoji to a song or playlist and then the boombeastic will draw the emoji on playback based on the song being reproduced).
Having a boombeastic at hand is not required to develop on Mopidy since you can run it locally on your computer
more info on Mopidy web clients here