How save user login and password in app

Question

I am new to objective-c. I've already made authorization window, using AFNetworking sent a POST request to the server. How can I make saving the login and password if the user wants. What would you every time a program is loaded, the user needs to press enter. What tool make this is? Here is the screenshot :

Answer 1

Keychain is a good way to store private data like password and username.
Search google as "Using Keychain to Store Username and Password"