The Best Friend List is an app the player can use to add friends they've played with, and send direct messages in New Horizons. The mechanic is similar to the Friends system in New Leaf.
For someone to be added as a friend, they will have needed for them to visit the player's island, or vice versa, and they will appear in the app. A Best Friends request can then be sent to that player. Once the request has been accepted, direct messages can be sent through the app, and mail can be sent through the Airport.
There are 5 tabs in the Best-Friends app:
- All - View the outbox, inbox and friends
- Best Friends - Shows all of registered best friends (only present when you have a best friend)
- Best Friend Outbox - View all pending requests that have been sent
- Best Friend Inbox - View all pending requests that have been received
- Friends - See friends that have been played with via networked play
Once at least 1 best friend has been registered, the minus button allows for the player to receive messages. Pressing "Y" to sends a message to all friends. The player can only send messages to a Best Friend when they are online.
It is unlocked when the island's gates are first opened for visitors or the option to visit someone using online play from "far away" is chosen. Orville will add it to the player's NookPhone.