iSHSHit is a new cydia tweak that lets you save and backup SHSH blobs on your iPhone, iPod or iPad itself. You can also send your saved SHSH blobs via email using this cool app. It also saves SHSH to Cydia using its On File service in the background and allows you to email the saved blobs instantly.
iSHSHit is available through BigBoss Respority in Cydia Store. After jailbreak, run cydia and search for iSHSHit to install it. After the installation is done, you will find the iSHSHit app on your iPhone springboard. Launch the app. Now tap on save and iSHSHit will get the blobs from Apple servers and save it on your device.
Here is the official description:
“iSHSHit allows you to back up device firmware SHSH blobs from Apple directly on your device for later downgrading. It automatically uses the Cydia On File service in the background, so it’s a great way to ensure that your SHSH is stored by Cydia. iSHSHit can also email your SHSH blobs to you for more permanent storage.”