While this idea is an extremely simple solution to a common problem, I find it novel enough to post simply because it has not been done, and I am convinced that it would prove to be useful.
Lost pet toys (especially dog toys). Pets often misplace or hide their toys while playing, causing owners to simply get new ones on a regular basis.
A survey of American pet owners in 2017 claimed that 4% of the pet owners they interviewed spends more than $250 on pet toys per month!
Simply installing hardware in toys that allow you to track it via a geolocating app, or even just emit a sound for you to follow when looking for your pet's missing toy. As I said, there's not much novel about the solution, except for the fact that it has simply not been done yet.
There are a variety of smart toys available for pets (at astronomical prices), but none of them has any form of tracking system installed.
Installing trackers on things that are easily misplaced is not a new concept, we simply have not done it for pet toys.
Looking at how much pet owners are willing to spend on their pets, now more than ever, should be a good indication that pet owners would be willing to spend a bit more to cut down on monthly toy expenses and to ensure the safety of their pet's favourite toy.