Let me just toss out a potential draw-back to these concepts:
Remote notification, as has been pointed out, most likely won't allow you to arrive home OR to notify the cops in time to prevent a theft. My home was burglarized a number of years ago. My mailman at the time was also a police officer, and his route took him down one side of my street and back up the other (my) side. He knows my house was intact on his way down, and he spotted the broken window on the way back. So they thieves weren't inside very long -- and that's normal. The pros are in and out within less than five minutes, and usually a LOT less than five minutes.
So the notifier won't save your firearms.
But many states either have adopted or are moving to adopt laws requiring notifying the police of a stolen firearm within ___ (24/48/72) hours of when you knew OR SHOULD HAVE KNOWN about the theft. So if you're out of town, on vacation or business or for whatever reason, the clock won't start ticking until you arrive back home. But if you have one of these apps that's supposed to send you a text message, suppose for whatever reason you don't receive the message, or maybe you accidentally delete it without reading it. And you don't actually return home for two weeks after that.
It's not a stretch to think that an over-zealous police officer or prosecutor might accuse you of intentionally ignoring the alert in order to give a hypothetical accomplice more time to dispose of the stolen firearm(s). So there's a scenario under which this "feature" not only won't help you, but could actually harm you.
I'm a Luddite. I don't trust technology and you won't see me lining up to buy whatever you develop out of this project. I'm also not interested in anything that puts a chip or transmitter in the gun. If my app can trace it, so can other people, and where I go with my gun is none of their business.