I developed a simple web application to test with ARI.
You can find it on github
You only need to put the html page in your asterisk /var/lib/asterisk/static-http/ directory, point a browser at the right address and start playing with ARI apis.
Aritester is a single page application with which you can connect to a stasis application, see all the related events and perform almost all the actions available on channels and bridges.
It's still in a development phase, I plan to add more features and improve the existing. Anyone wanting to help (especially by improving the CSS ) is welcome!
[For the asterisk guys: is there a chance to add aritest to the asterisk sources (like e.g., ajamdemo.html)?]