“Once in a while, give Glass-Apps.org a visit and browse through the Glassware listed on the site. Some apps are the official apps Google has already provided you access to, while others are third-party apps. Keep in mind that the current restrictions placed by Google on developers and use of the Mirror API (used to power Glassware) is pretty tight, so not all apps will work as expected (and some won’t work at all due to hitting API limits).”
Clipped from Cnet.com
http://howto.cnet.com/8301-11310_39-57612165-285/five-tips-for-a-google-glass-newbie/