With the new release of facebook ios sdk, the documentation is talking about the facebook like control, that allows to like a page. https://developers.facebook.com/docs/ios/like
You can use FBlikeControl button by enabling below feature in viewdidload or where you create FBlikeControl button:
[FBSettings enableBetaFeature:FBBetaFeaturesLikeButton]; [FBSettings enablePlatformCompatibility:NO];