Is there way to save google maps for offline iphone without jailbreak I've iPhone 3Gs and want to download Google maps to use them offline with GPS.

So is there a good app do that for me ?

Note: i don't want to jailbreak my iPhone.
No, nor will you find one (in the official App Store). Storing the image tiles breaches Google's data licence. There are a bunch of apps that use OpenStreetMap, which has a more liberal licence.