There was a startup in US about 3 or 4 years ago who implemented this system for realtors so they can share the houses to potential buyers. This technology can be implemented in everything that requires a key.
Thinking back at it, I don't get why nobody have done this earlier, or did they?
Thanks for your posts @danizaharie!
I read everyone of them and they always open my mind to new opportunities or ways of seeing things!
Keep on going!
Alin