There Day is a Supercell game that was developed to play on mobile phone platform, on Android, IOs, etc. But in addition, we can link it to our social networks like Facebook, or Google, to save the progress of the game.
How to link and unlink Facebook from Hay Day
This explanatory video shows how to link and unlink the Hay Day game from the Facebook social network.
From facebook you can open the Hay Day app if it is linked to your social network account, it does not mean that Facebook has the built-in Hay Day interface, but rather the ability to serve as the game's launcher, so you can enter there .