Recently I came across an App for iPhone which works similar to the Firewall for Desktop computers. Firewall App for iPhone and iPod Touch will alert you whenever an app tries to access the internet, data or AppStore. This Firewall for iPhone sits in the background and monitors all the Internet connections.

Firewall for iPhone is broken into two parts and the first one mobilesubstrate component, handles all the low level functions such as in-application firewall changes, network traffic management and more. This component will prompt a display when using a network-enabled application similar to common desktop firewalls. This displays multiple options like Allow once, Deny once, Always allow!, Always deny!, Allow all for this App and Deny all for this App.

The other part of the Firewall iPhone App application is a rules editor. Here you can edit and manage the rules that you have added to any iPhone App. You can easily select an application from your list and edit the rules for that particular App.