During Google I/O 2013, glass team announced that Glass Development Kit (aka GDK) is under development and will be released soon.
As an update, couple of days ago glass team notified that, they are still working on the GDK and gave an alternate path by advising to use Android SDK (since glass is built around android platform so that developers can start experimenting their glass app ideas).
They’ve also announced 3 new glass app APK samples for Compass, Level and Stopwatch glass apps. All the source code for the glass apk’s are available on GitHub here.
Glass Development Kit or GDK information is available here
Since glass is built around Android 4.0.4 platform, as a developer you should be able to immediately start coding and testing your glass app idea on an Android emulator or device. Once you have the actual device and GDK you should be able to experiment with real a glass experience.
Here is the announcement from The Glass Developer Relations team
At Google I/O, we announced that we are actively working on a Glass Development Kit (GDK) that allows you to build Glassware in the form of APKs. We’re still hard at work on the GDK, but in the meantime, you can start designing and developing your awesome ideas with the existing Android SDK. Although you won’t have all the tools necessary to design the perfect experience for Glass, developing with the Android SDK (API Level 15) lets you try out ideas while you wait for the GDK.
For you seasoned Android developers, your background will get you a long way in building Glassware. You’ll find out that some features that you want in the GDK are already supported by the Android SDK, such as accessing the accelerometer or playing media. If you’re an Android beginner, take this time to learn about general Android development, so that you’ll be ready when the GDK launches.
To help all of you get started, we wrote some APK samples that include a stopwatch, a level, and a compass, and we plan to release more in the upcoming weeks. When we release the GDK, we’ll update these samples to demonstrate the migration path between a traditional Android app and a full Glass experience.
As always, we look forward to seeing what you build!
Happy coding and fun with Google Glass. We’ll inform as soon as we know about the availability of Glass SDK.