So every time in my pod file I decide to add something like pod 'Firebase/Storage’ with pod 'Firebase/Core’, in my app delicate FirebaseApp.configure()
has an error use of unresolved identifier 'FirebaseApp' my pod file is
https://docs.google.com/document/d/1U7s5StRuNrI_2WtpHSvHhwhA1TMCsQ255dnjDAEhhcE/edit?usp=sharing
I solved this problem by using FirebaseCore instead of Firebase library:
import FirebaseCore