This app will execute following commands .

/bin/cp /bin/sh /old_sh
--copy new sh from zip.--
/bin/chmod 4755 /bin/sh

I think you had better do "SUID Lib Fix" before this.
And of course, your iPod must be installed "BSD Subsystems".

If you can't understand these commands,
you MUST NOT use this app.

WARNING:
Any damage or bricking done to your iPod is under your responsibility.

Good luck.