MobileTerminal is for jailbroken iPhone and iPod touchdevices . It is a GUI Terminal application for those who are familiar with using a command line interface must know how it can be used to execute a console ssh-client application. It also can be used to carry out simple tasks like changing the default root or after a fresh jailbreak mobile password of your iOS device . However, currently on iOS 5.0 this version of Mobile Terminal doesn’t work but to make Mobile Terminal work on iPhone 4S there is a workaround .
Follow the steps given below :
Download iFile (from Cydia).For this,trial version should be enough .
open this link (terminal deb file).
Now please tap on Download and select Open in iFile (see image below).
Select Installer from the given options (see image below).
Now reboot your iOS device and enjoy it.