If you are like me and you have a old iPhone and you don't want to buy a new one, you can fake your ios version by fallowing this tutorial. Just to be safe i am not responsible for what you do with this or if you mess up and wreck your phone. Plus ios and iPhone all belong to their rightful owners.
Get OpenSSH or iFile from cydia. For iFile i recommend either the insanelyi source (http://repo.insanelyi.com).
If you are using iFile hit the back arrow until you see a / (Forward Slash) on the top of the screen.
Scroll down and press the system folder.
It is the only folder in the system folder.
Scroll down and go into the core services.
Look for the key that says <key>ProductVersion</key>. And edit numbers in the string below it. Just to be safe you might want to remember the default numbers. Right now i am running 6.0.1 on my iPhone 2g...
After you edit it press the blue button that says done. Close iFile and then go to Settings>>>General>>>About. And for version it should be what ever number you changed it to.
This will work for some Cydia and AppStore apps but not all of them. Hope this helps!!!!