This is a web app that I built to see if it was actually possible to create an application that runs at 60fps on modern smartphones. For the most part it was successful. If you're interested, there's a blog post you can read.
Note: the source code is not heavily commented as yet. As I have time I will try to put some time into doing that. Hopefully it will be readable as-is, but I apologise if you run into readability issues!
If you're interested in dissecting the app start with /src/misc/bootstrap.js and /src/app.js. The <canvas> based components are found in /src/view/ticker.js and /src/view/dial.js.
The dial component, since it is used for both weight and height entry has a wrapper component that configures it found at /src/view/dialentry.js, and the weightentry.js and heightentry.js then use that. Overly engineered, I know, it's all a learning process!
This application is © Google 2013. Please see the LICENSE file for more details.