NemusSync

NemusSync is utility(Native App) for iPhone/iPod Touch which sychronizing application with Google OVER THE AIR.
For now, support Calendar only.

Install
1. Install
You can install it from "BigBoss's Apps and Things" repos.
Just update community source and find "NemusSync" in System category from AppTapp 3 Installer or Cydia.
2. Set TimeZone
TimeZone of iPhone and google must be same.
3. On iPhone :
Settings > General > Date&Time > Time Zone (System/Calendar)
4. On Google :
1. Setting > General > Current TimeZone
2. Setting > Calendar > (Choose Calendar) > Calendar TimeZone
5. Configure

System Requirement

* Jailbreaked iPhone or iPod Touch 1.1.1 ~ 1.1.4

Source.