It was revealed yesterday that the first round of Google Glass devices are finished. Google will start shipping to those who pre-ordered the device at Google I/O last year first, and those developers will presumably start building apps for the hardware immediately.
Google Developers was updated today with the Google Mirror API page. The page contains all the information you need to start building apps for Google Glass. The page also includes a number of videos to walk you through specific actions of the API:
If you need help getting started on Glass development, Google has released two starter projects in Java and Python that can be loaded into App Engine. From there, developers can use the starter project as a foundation for their own projects. If you need the API in other libraries, you can grab it in Java, Python, Go, PHP, .NET, Ruby and Dart from here.
Once developers have the tools they need, they will also need to follow the rules. In the Terms of Service, Google says quite plainly that Glass developers can not serve ads in their Glass apps, nor can they charge for them. Google also says that all Glass apps must be hosted on Google's own distribution channel "unless otherwise approved in writing by Google."
It seems that Google isn't quite ready to monetize Glass, but it will probably allow developers to start selling apps later this year once the device goes into mass production. It would make little sense for the company not to. Either way, we've reached out to Google for comment and clarification and will update if we hear back.
EDIT: A Google spokesperson gave us the following comment:
"Developers are crucial to the future of Glass. The focus during the Explorer Program is on innovation and experimentation, but it's too early to speculate how this will evolve."