What is 'Manage FB app" and what it does?

1) Mange Fb app is used when you wan't to add facebook page tab to your facebook account

2) Using Manage FB app ,You can add your campaign in leadlock on facebook page tab

3) To get your Facebook App id, go to your Facebook account ,Click on Manage Apps

4) Select your Facebook App, click on dashboard page

5) Copy App id from  App id field and paste in Facebook app id field in Facebook app setting which is on Manage FB App page