1) Close all Apps that are running
2) Open Cydia, press "Manage" along the bottom and then select "Packages"
3) Select AppSync from the list
4) Click "Modify" at the top right corner
5) Then select "Remove" from the pop up menu then press "Confirm" - This will now remove AppSync.
For the next part you will need either iFile (on the device can be installed via Cydia), i-FunBox (on your computer) or iExplorer (again on your desktop)
6) Using one of the above tools navigate to /var/mobile/Library/Caches
7) Locate com.apple.mobile.installation.plist and delete the file
8) Locate com.apple.LaunchServices-045.csstore and delete the file
9) Now Reboot your device
10) Upon device reboot you may notice that some of you app icons are missing don't be alarmed this is normal it can take a few moments for them to recache and fall back onto the SpringBoard.
11) Once all your apps have re appeared you can open the weather app as normal
