4.2, and as was revealed recently, Glass is running Android 4.0.4 Ice Cream Sandwich.To be clear: Glassagram is not an Instagram app for Glass. The only thing the app does is add options to put filters on your Glass photos before you share them. The stock Android camera does offer photo filters, but only in Jelly Bean
The process is actually a bit cumbersome with Glassagram. In order to get filters on your photos, you have to share the photo with the Glassagram service first. It will then apply all available filters to your photo and send the pack back to you, where you can then choose the best option. It's definitely nothing revolutionary, or even likely the best way to accomplish photo filters on Glass, but it is an interesting app in these very early days.