The penny dropped for me last weekend when I enabled the guest wifi because we had friends staying over. Remember how we basically all said…
…but that’s just it… they live on “our” phones. Sharing your smart home is possible with Apple Home of course. You can’t limit the items per room and only give limited access. Neither can you share with Android users nor with people who don’t use their phones for things like that…
So I figured make the key cover as big as an iPhone to give enough room for the key, so that the different shapes and sizes don’t matter as much. Also, add the smart home capability, so that I can basically hand friends and family when they stay over a “loaner phone” so to speak, only that it doesn’t have a screen.
So with this one, you can now control lights and climate in the guest room. Plus, you got the key for the windows and the terrace door. Nothing I’d need for myself, because I have all that on my phone, but great to hand out to guests.
…oh yeah, and then the little easter egg for everyone here…
…I made it a “car” again 
. A nice inside joke, but also strangely comfortable to hold in your hand. Anyway, it felt useful to me, not sure if the judges will agree with something that is iPhone sized when they asked for key covers, but we’ll see…