XiaoMi makes great value hardware, this app simply connects them all to your network. Unfortunately this app is hot garbage, firstly the mandatory signup/reset/authentication process is painful and often doesn't work at all; then you can add devices either with a QR code of you have one or with the model name (if you don't have the QR or know the exact model it can be difficult to find); firmware updates are listed as available but never download, the process is much easier with other brands.