UPDATE November 2013
Maybe u have 2 account facebook or other, so u no need to sign out and sign in everytime. Here, I will share with u how to install same app twice or duplicated it. I am using iFile to make it.
1. First open up cydia
3. Goto search and search for Application Duplication and install it.
4. Download this AppDub, extract and overwrite in /usr/bin/
6. Now open mobile terminal then type :
And type :
appdub -a Facebook.app
And let it run until finish.
Look this How to change app display name
I haven’t try it if the app have update. If it not support when update, you need to do again from step 6.