I got from a friend a folder of app store application

My iPhone is 1.1.4 unlocked & jailbroken. Installed installer and openSSH.
But i've never install an application from my PC, i've just download and install things from installer. So what should i do to install the BB.app from my computer ?

I tried with iPhone PC Suite, copy the BB.app folder to /Application on the iPhone, but the application is not appear (i don't see it to launch it).

Sorry for my broken English. Any help would be appreciated!

Thank you,