"You can use the comgooglemaps URL scheme to launch the Google Maps app for iPhone and perform searches, direction requests, and display map views. When you launch Google Maps your bundle identifier is automatically sent as part of the request."
"Before you present one of these URLs to a user in your app you should first verify that the application is installed. Your app can check that the URL scheme is available with the following code:
[[UIApplication sharedApplication] canOpenURL: [NSURL URLWithString:@"comgooglemaps://"]];
"
https://developers.google.com/maps/documentation/ios/urlscheme