I'm currently using the official firmware 0.9.9.2 with the 1.0.833 app. I'm a bit disappointed with the device. It's quite accurate when it comes to sleeping but I have 2 main drawbacks :
- it's not accurate at all when it comes to steps. I hardly practice when I'm staying home and the MiBand is registering lots of steps. It's good enough when I'm actually running. I do wear it on my right wrist and I'm right-handed.
- battery life is not on park with what others people are getting or with what has been advertised. My MiBand doesn't last very long. After 10 days, and it was fully charged, I'm down to 33%. It is synced with my MiPad, so notifications are kept to a minimum (no alarm clock, no call vibrations, only unlocking feature on). I use the MiBand daily and I go to the gym 3 times a week.