You should make it clearer that you don't actually handle voice recognition. When I read: "Developers use Wit to easily build a voice interface for their app." I expect you to handle things from start to finish.
Also, let me try it! It's frustrating because the UI looks like you can experiment but it's only an animated demo (or am I missing something??) In particular the mic logo is used to record on Google and here it doesn't seem to do anything?