Although this would seem a rhetorical question, I'm asking because I am developing one, and I am asking to sense the level of interest.
What I have currently working is a text interface that allow you to type in things like "Raise the dinner lights" or "Lower the house by 2 degrees". All the natural language processing works, and I am now going to work on the voice integration so you can say these things instead of type them (although you will always be able to type them).
This interface will never replace Indigo's screens, or even the Indigo iOS app. It's simply an easy way of saying commands like "Set the house in Away mode", which is easier than firing up the interface on your iPhone and tapping around to find your Group that sets the house in Away mode. My goal is to have most of your daily interaction with Indigo done by talking to an app on your iPhone. I like to think of it as a streamlined way of getting things done with Indigo.
Also note that app will only run on iOS and it will require your Indigo server be accessible from the Internet. It is designed in full compliance with Indigo's and Apple's terms, so I doubt there is anything Apple could/would do to break it. It will be free to the those who help me test it, but there will be a small fee once it's up and running.
Any interest in using, and possibly paying for, this product once I am done (hopefully in the summer of 2014, but that's just a guess)?