"Q2: Can use smart alarm clock when leave the phone? A: Certainly can, or else how to call smart alarm clock? After pair Mi band, set once in the Mi band app, and then switch off the phone, no problem."

I still need a phone to set it though. I'm still using a 64GB iPhone 4S, and I don't plan to buy a new phone just so I can set up another alarm clock. In fact, if I buy another phone, then I can just use that as the secondary alarm! (but it wouldn't be silent)

I'm using the first gen Mi band and the app works just fine on my 4S.