Fitbit app

I just got a Fitbit One, and I'm running the Fitbit app on my iPhone 5S.
I thought I read somewhere I could see the battery status in the app, but can't find where. Can I do that?
Can I do things like update my weight or other data? I needed sighted help to put in my weight in the first place.
Any other Fitbit hints people might care to share?
Thanks.