Redsn0w 0.9.11 b4 adds the native jailbreak support for iOS 5.1.1 on all A4 devices. This version removes the need to point Redsn0w to previous version while performing the tethered jailbreak on iPhone 4, iPad 1, iPhone 3GS and other A4 device. Now we have to select the latest iPSW using the “select iPSW” option so that Redsnow fetches the required files from this new version.
Redsn0w 0.9.11 b4 also brings the Stitching feature for iPhone devices. After building a stitched iOS (iOS + blobs), we can downgrade to this stitched firmware even if the Apple’s signing window is closed or SHSH blobs are not available/accessible.
The users who rely on ultrasn0w based unlock can also use this new version to cook the custom iOS 5.1.1 firmwares while preserving the baseband. Later, they can jailbreak their device with this same version and install the Ultrasn0w from cydia to get the signal. However, it is to be noted that Redsn0w 0.9.11 b4 provides tethered jailbreak on A4 devices only.