Facebook Login is a fast and convenient way for over 2.5 billion people to create accounts and log into your app across multiple platforms. It's available on iOS, Android, Web, desktop apps and devices such as Smart TVs, and "Internet of Things" objects. Facebook Login enables two scenarios, authentication and asking for permissions to access people's data. You can use Facebook Login simply for authentication or for both authentication and data access.
When people choose to login with Facebook, they can share their real identity through their public profile. Public Profile includes a person's real name and a profile picture. Apps based on real identity often have less spam and foster higher quality conversations.
Easy gradual authorization so you don't have to request all the information you want up front, you can do it over time. As their experience with your app deepens, you can request additional information to further enhance their experience.
Great experiences start by giving people control. With Facebook Login, people can choose which information they share with your app. They can still get the benefits of logging in with Facebook even if they feel uncomfortable granting access to certain information.