How to install 3rd party Iphone Apps on OS 3.0

- You computer need itunes 8.2.1 to be installed.
Download here: http://filehippo.com/download_itunes_32/

- Then your Iphone 3g/3gs must be jailbroken with OS3.0.
HOW? click here http://iclarified.com/entry/index.php?enid=4447

- Now plug your iphone, go to App Store, download any applications from iTunes store and sync into your iphone (this step is a must. If you miss this step, your cracked .ipa wont be installed into your device)

- You need wifi on your iphone in order to add sources and install Appsync

- After jailbreaking,you would see Cydia on your SpringBoard. Now open Cydia
Cydia > Manage > Sources > Edit > Add > type http://cydia.hackulo.us

- After verifying the URL, press on Return to Cydia then press on Done.

- Now click on the source you just added above, then install Appsync. Respring your device

- Finally drag the cracked .ipa into iTunes Library and sync into your device.

Enjoy

Hope the above torturial will help you out.