Spinner
AnimationCanvasHTML UI
This is maybe not the most useful tool but it's useful enough that there are
about a billion of them on the web. Basically it's a digital game spinner that
lets you pick from a number of choices.
The main challenge of this is figuring out how to animate the spinning of a
wheel (or, alternatively, an arrow in the middle of the spinner.) You should
look
at rotate()
and related methods on the CanvasRenderingContext2D class.
This tool will probably use a combination of HTML and Canvas UI. Canvas for drawing the spinner but HTML for configuring it. Ideally the user can specify the categories they want and maybe, if you want to be fancy, how likely each one is.