Pic from omaq..
The most eerie thing that comes quickly to parents mind is when they could not see or hear their child in a busy shopping mall. Announcement of a missing child in a supermarket is not something strange this day.
So the most conventional method of dealing with it are like put them together in the shopping cart or just hold hand together. Other than that you can try latest gadget on locating your child. It’s like they are making Agent Bond equipment for mass production.