The University of Washington’s Mobile Accessibility department has been prototyping applications that use mobile devices to solve particular accessibility problems. Their projects have used multiple sensors within the device, from accelerometer to camera. Example projects include detecting alarms for hearing impaired to using a phone as a virtual cane for navigating open spaces.

The projects are open source and you can easily download the source code and Android APK files for testing and developing. Many of these projects could easily be integrated into a Glass product. Visit their Projects page for a list projects. You can also visit the collections on their Google Code page.