Im opening a map like this:
NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps?q=%@,%@", destLat, destLong];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlString]];
Is there any way to choose with which app will open the map? For example, Safari, or the maps app, or Tom Tom app…
Yes, you should use one of the iPhone URL schemes. There is a pretty hefty list available here.
Note that you should first check if the application you want to launch is available before using a certain URL scheme.