Not to mention that the whole app thing will rely on a server and a functional internet connection, so you can forget about interacting with your alarm system i

Not to mention that the whole app thing will rely on a server and a functional internet connection, so you can forget about interacting with your alarm system if there's a cloud or network outage. I feel like modern-day developers have effectively forgotten how to do local network communication. I know about NAT traversal and similar problems, but you can still architect your system in such a way that your cloud backend is a dumb NAT traversal helper/proxy, which then makes it trivial for your client to offer a cloud-less, local connection option for those users that know how to forward ports/have IPv6/etc (or when you go out of business and your cloud service goes offline).