Actually, I've narrowed it down to anytime I'm using multitasking, and switching between apps. That is repeatable, but, not consistently. It ONLY crashes for me when I'm doing that, and even more likely if I side-scroll through the recently used apps. It makes me wanna stay away from double tapping the home button.
It does it on both my iPhone 5S, as well as my iPad Air.
And, it's not really a "crash" as much as it is a small "reboot" of sorts. It doesn't last long, and is back to normal within seconds. If it were an actual reboot, that would take minutes to reload. But, nonetheless, it's still maddening.
I'm glad they're finally acknowledging the issue and will provide a fix, at last.