The DIY Nook is an application that offers Animal Crossing recipes. You can browse through them and learn to make different DIY recipes. You can also filter them by type or series. For example, you can search for Furniture, Walls, Floors, Clothing, Caps, Tools, Wands, etc. 

The recipes you learn in Animal Crossing are not only for furniture, walls, floors, clothing, hats, tools, wands, but also for everything you can think of. You can use the app to keep track of the recipes you are learning in the game and filter them to share them with your friends or see how many you are missing.