This ROM includes the GDR2 update from Microsoft, which brings the FM radio to compatible devices and the Data Sense app which allows you to track your data usage by telling you which apps are using most of your monthly allowance while reminding you how many days are left in your billing cycle.
The ROM also includes the Amber update which is Nokia's inclusions to GDR2 exclusive for their Lumia lineup. You will get the Smart Camera app with the Action Shot mode, which allows you to snap an action sequence and have it come out as one photograph. You always get the always-on clock and the double tap-to-wake among other features and enhancements.
If you are interested in trying them out on your device, you can download them using the following link, which include instructions on how to install the updates
- Download unofficial Amber ROM for your Nokia Lumia 920
- Download unofficial Amber ROM for your Nokia Lumia 820
If you are not confident in installing this unofficial ROM, it is better that you wait for official update which has already started its roll out.
source - NokiaViews | Engadet