Being able to unlock your house from outside... already done
I made the mistake of adding an August Home Smart Lock to my front door. It's an Apple HomeKit device so it requires a hub for Siri; either an AppleTV or iPad. I use an iPad Pro in the living room for this purpose. I was showing off my home automation setup to a neighbor a few days ago, he's cool techy guy like myself. Fast forward to this morning, I'm pulling out of my driveway and he runs up and asks to borrow some flour to fry wings for an office wing party/contest; dope. So I put the car in park and to go back inside and he's like "I'll let myself in." I'm stunned, like what the f*ck. Dude walks up to my front door and shouts, "HEY SIRI, UNLOCK THE FRONT DOOR." She unlocked the front door.