Something not working, or an idea for Toybin Sort? Write to javier.bascones@gmail.com — you'll get an answer from the person who made it, usually within a couple of days.
Not yet: UNDO works even then. Take back a move or two and try another order.
It asks a solver for a move that still leads to a cleared shelf, and highlights both bins.
No. The game has no networking code at all.
No. It is a universal purchase: buy once and it works on iPhone, iPad and Mac with the same Apple Account.
iOS 15 or later, or macOS 11 or later. The game runs entirely offline.