How to get FieldTest application icon to always show up on the iPhone

iPhone 3G 2.2.1, jailbroken

The preferred way to bring up the FieldTest application on the iPhone is to type *3001#12345# and press Call. My iPhone always responds with the error "Error performing request. Unknown Error." Here is a way to always have the FieldTest icon always appear on the Springboard.

1. Bring up a terminal on the iPhone, or ssh into the iPhone.
   
2. Become root by typing su [enter]. The default password for root is "alpine"
   
3. Change to the FieldTest.app folder by typing: cd /Applications/FieldTest.app [enter]
   
4. Make a backup copy of Info.plist by typing: cp Info.plist Info.plist-factory
   
5. Change the Info.plist file to xml format by typing: plutil -c xml1 Info.plist [enter]
   
6. Edit Info.plist using vim or nano and delete the following lines:
   
   <key>SBAppTags</key>
   
   <array>
   
          <string>hidden</string>
   
   </array>
   
   
7. Change the Info.plist file back to binary format by typing: plutil -c binary1 Info.plist
   
8. Restart Springboard by typing: killall -15 SpringBoard
   

If you find yourself in a bind and want the old Info.plist back, you can restore the factory copy.

1. Bring up a terminal or ssh into the iPhone.
   
2. Become root by typing su [enter]
   
3. Change to the FieldTest.app folder by typing: cd /Applications/FieldTest.app [enter]
   
4. Restore the factory Info.plist file by typing: cp -f Info.plist-factory Info.plist [enter]
   
5. Restart SpringBoard by typing: killall -15 SpringBoard [enter]