Indoor cats are less interesting. I'd see food bowl, water fountain, litter box, bed, couch, maybe a view out the window now and then.
He has a GPS tracker in the works.
Very useful for indoor/outdoor cats, I don't recommend it but sometimes it is the only way to give a former feral a decent life.
And great for all dogs, if I were a dog owner, I would buy one in a minute.
Most microchips are not readable by all readers, companies making the microchips are still not working together to make an universal reader.
I would love to see all beloved pouches fitted with gps trackers. It would make it much easier for them to be found and less likely to end up lost forever.