Band periodically crashes for a small number of people for the same reason that _all_ other apps crash. Please feel free to search the forums for evidence. Unfortunately no one seems to be able to say officially why this is, but the fact that it happens with _all_ third party apps leads developers to believe that there is currently a firmware or SDK bug. Until more information is provided by Apple on this then there is nothing us developers can do about it.
Oh, the 2.0 firmware is most definitely buggy as hell, and I've had more problems opening up native Apple apps (like Settings) than 3rd-party apps. A firmware fix can't come fast enough!!
HOWEVER, there have definitely been cases of 3rd-party apps that have had more stability problems than others too. EA's SCRABBLE was one example. I didn't know
anyone who could get that app to work at first, no matter what they did -- but then they provided an update, and now it works fine. So while Apple's buggy firmware is certainly to blame for a lot of the crashes people have, it's not the ONLY problem.
I'm not saying BAND is one of these problems, and my apologies if I mistook it for being one from just a few comments. If that's not the case, I'll certainly reconsider it. It's always been an "almost buy," for me anyway -- but I'm trying to budget myself with apps, and there have been other ones I downloaded first for practical needs (while Band seems more like a "fun" app, which I'll get eventually).