The "hook" is within your AppDelegate.
Implement the following method...
- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation
{
NSString* tUrlString = url.absoluteString;
// ... analyse tUrlString
// ... do something
return YES;
}
Furthermore you have to register your app for reacting to the "myapp://" URL scheme (if not already done). This can be done in the "URL Types" within the "Info" section of your app's target.