If you’re looking for a security system, I’d suggest using something purpose-built.
SmartThings has tremendous promise as a platform, but its reliability just isn’t there for home security applications. That’s just an opinion, of course. YMMV. Also, the Windows Phone app doesn’t seem to be a high development priority.
I’d recommend reading some of the threads on “Smart Home Monitor” on these forums. There is also a community-developed Kwikset 910 Device Type that I believe should do what you’re looking for. (Don’t quote me on that though - I don’t trust ST with my deadbolts yet.)