This circular control plugin for D3 is the main UI control of my recent metronome project. I’m not sure if I’ll ever finish the metronome, as I already found a really good one with timer, which I especially sought after, as well as loads of other features. I still decided to release this control as proper D3 plugin with unit tests and documentation. If you’re looking for basic example/template for D3 plugin, see http://bl.ocks.org/cpbotha/5073718.

Source code & documentation:

https://github.com/lloytynoja/d3-circular-control

Screenshot (default color scheme):

By the way - if you’re in need of decent metronome, check this out: Tempo Advance. Best metronome app I’ve seen, hands down.