You don’t have to wait to get a taste of what Android 4.0 Ice Cream Sandwich will be like on your Nexus S phone. We wrote some teaser photos of this port a few days ago.
Thanks to a few developers, you may now download and flash ICS to your device. It seems this port may only be for fellow developers as this one seems to lack WiFi and Bluetooth for now. This build is only tested on the Sprint Nexus S 4G.
Download Ice Cream Sandwich Port for Nexus S
