Here is a how to install corona to untether jailbreak iOS 5.0.1 based device (iPhone, iPod touch and iPad), Corona is the work of Chronic dev team that was based on Pod2G project -- untether userland jailbreak.
Before installing make sure your A4 devices already jailbroken, because it's a requirement to install Corona:
Open Cydia from SpringBoard and then search Corona who is provided there, when it appears tap on "Install".
