Animal Crossing: Happy Home Designer is a game for the Nintendo 3DS that was first announced on the 4.1.15 Nintendo Direct. It released on September 25, 2015.
Animal Crossing: Happy Home Designer is compatible with all Animal Crossing amiibo cards EXCEPT for the RV cards made for Animal Crossing: New Leaf. Scanning a card to your New Nintendo 3DS or via NFC Reader will allow the villager on that card to visit a home the player has designed, or replace NPCs in public works the player has created such as the school or hospital.
Once the amiibo phone is unlocked (after a few in-game days), the player can use amiibo cards to contact and decorate for specific characters that might not otherwise appear in-game. Using the phone to scan a Villager amiibo will unlock a golden statue of the generic Super Smash Bros. Villager to use in house decorations.