Tuition and drills in music theory. HTML5, Javascript, CSS. Originally here: http://voices.azurewebsites.net/.
TODO: one improvement that I have in mind is adding iPhone (and possibly iOS in general) browser support for the drag-drop on the "clock"-type controls (e.g. where you'd drag-drop the natural note "C" to the five-after-the-hour mark to make it C#). Doing that causes the browser itself to scroll on iPhone (for both Safari and Chrome). But it works on mac os, Windows Phone, Surface, PC, etc, etc. So evidently the iPhone's browser is not respecting the "don't scroll the page" property on the canvas.