If you have actually blocked somebody accidentally or changed your mind about the block, however, it is also reversible. You can alter your Privacy settings to unblock and enable somebody back into your Facebook world.
How To Unblock Someone On Facebook App
1. Click the down arrow beside "Account" at the leading right of any page on Facebook.
2. Click "Personal Privacy Preferences" from the Account menu.
3. Click the "Edit Your Lists" link under the Block Lists heading. It is at the bottom center of the page.
4. Click the "Unclog" link next to the name of the person you wish to unclog. A list of individuals you have actually blocked is discovered under the Block Users section.
Suggestion
Unblocking somebody does not instantly put that person back in your friend list. You must include the recently unblocked individual as a buddy and wait for them to verify the demand.
And one more thing please don’t forget to share this awesome trick to use the How To Unblock Someone On Facebook App with your friends.