add method in application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

i want integrate a 3rd party sdk in my project. i need put init action after the app launched in the metod “application:(UIApplication )application didFinishLaunchingWithOptions:(NSDictionary )launchOptions” in IOSAppDelegate.cpp file. i don’t want modify engine source code. How would i do?Thanks!