I read about Spritz a short while ago. And I thought it was really cool. The problem is that Spritz Inc., the innovators behind Spritz weren't going to provide an implementation or SDK or whatever that I could use in the timeframe I was interested in. I assume that their implementation is better, so definitely check on them as they said implementations are coming and they will possibly be free to use.
In the mean time, I have made a JavaScript implementation that you are free to use or modify under the MIT license. I will pencil in that it is the "don't ask me" license as well. You can use it more or less in any way you see fit if you don't ask me anything about it. My slowly evolving code will be posted to Github. I also have it on CodePen and jsFiddle.
Also, for the Android crowd, be sure to check out Glance. It is a neat project which also has it's source code that can be found on Github
