Simple GDK example acting as a compass. In addition to the visual display, you can tap the touchpad to have Glass speak your current orientation aloud.
GDK sample application that lets multiple people play a simple Charades game.
A GDK sample that receives audio input from the microphone and displays it on the screen as an animated waveform, along with the decibel level.
A Mirror API sample project that illustrates the creation of a counter Glassware