Once an Apple device is jailbroken, one of the things done by many folks is to install apps from Cydia store and to also install apps that were not permitted into the Apple Store but found elsewhere aside Cydia e.g Vshare and AppCake.
The thing is, without AppSync installed on your device, none of the apps downloaded from non-Apple Store would work. Another problem is that old versions of AppSync do not work and some are having trouble getting the new version to work.
The guide below will show you on how to install a working AppSync on your Apple device. Its being tested and it worked on all test devices. This tutorial is meant to help you install apps outside the Apple App Store and not to promote piracy.
1. A jailbroken apple device on iOS 8.0 - 8.1
2. Internet Connection on your apple device
1. Launch Cydia on your phone and click on Sources at the bottom
2. Tap on Edit at the top-right orner of the screen and then tap on Add at the top-left corner of the screen
3. when the box appear, type in http://repo.hackyouriphone.org and tap on Add Source
4. Tap Add Anyway when prompted about the integrity of the source
5. After download of source is complete, go to Search at the bottom and then type in AppSync Unified Beta
6. Install the package and then reboot your device.
7. Once reboot is complete, try installing any ipa. package downloaded from any store aside App Store to confirm that its working.