TinyUmbrella

TinyUmbrella is a smart utility that can revert your jailbroken iOS device to a previous update. It manages to do so by backing up SHSH blobs for your phone, which makes it possible to downgrade to another firmware.

Firmware details automatically gathered

Jailbreak operations don’t always pay off – discontent towards the performance or features of the new firmware is a plausible scenario, to which many users can testify. In this type of situation, the solution is a third-party application that can revert the jailbreak, so that you can go back to your old settings.
The application relies on Java Runtime Environment to function, so it's a good idea to check whether or not it's on your PC, even though it's already in the deployment package.
One of the programs that can achieve this is TinyUmbrella. This is a great first hand solution to a jailbroken device that you wish to restore to a previous firmware version.
The algorithm it’s based upon is quite complicated and requires a great deal of tech knowledge to fully understand. In a nutshell, TinyUmbrella automatically retrieves the current firmware (SHSH blobs), then saves it locally and sends it to Cydia, which preserves it for later use.

Be sure you know what you're doing

Using a TSS server, the restore operation is facilitated at once. If, for some reason, the server is down, you can use iTunes to perform the downgrade.
A less happy scenario is the one where Apple stops signing a certain firmware update. It’s common knowledge that the company allocates a limited period of time for signing a specific update and so, when the interval is over, there is no possible way to retrieve the SHSH of that firmware.
If this occurs, TinyUmbrella will display a suggestive messages such as ‘You are too late’; even so, you might find a solution in iFaith, which extracts the SHSH blobs directly from your device instead of Apple’s or Cydia’s servers.
However, in order for this to work, the firmware you wish to downgrade to needs to be located on the device, otherwise it won’t pay off.

To conclude

On an ending note, TinyUmbrella is a great solution for restoring your iOS device to a previous firmware that worked better for you. It sports support for the latest iOS versions and updates are rolled out pretty often, which means it can lend a hand even for the newest devices.