As a user I want to log in the App by Facebook account, so that I can use all the functionalities.
Acceptance Criteria: I enter to the App, I see a Facebook icon button, which redirects me to enter my Facebook username and its password, so I can log in.
As a user I want to log in the App by Facebook account, so that I can use all the functionalities. Acceptance Criteria: I enter to the App, I see a Facebook icon button, which redirects me to enter my Facebook username and its password, so I can log in.