From basic cat flaps to cutting-edge smart cat doors with AI prey detection, we've reviewed them all to help you make the right choice.
See our definitive 2026 rankings below.
Goal: complete ~2000 solved-problem exposures by systematic study and spaced practice.
: Teaches "shortcuts" and the quickest strategies to reach a solution under time pressure.
A comprehensive resource of 2000 solved problems in discrete mathematics should cover a wide range of topics, including:
Prefer official or open-access copies. If a PDF isn’t freely offered by the author/publisher, obtain it through purchase or library loan.
The content spans the foundational and advanced areas of discrete mathematics:
The path to a reliable AI cat flap is strewn with failures. These projects serve as cautionary tales in a market that's hard to get right.
Overpromised on Kickstarter and failed to deliver. The project appears to be abandoned.
The company behind the original KittyFlap product went out of business due to failures with delivery and customer service.
Goal: complete ~2000 solved-problem exposures by systematic study and spaced practice.
: Teaches "shortcuts" and the quickest strategies to reach a solution under time pressure. 2000 solved problems in discrete mathematics pdf
A comprehensive resource of 2000 solved problems in discrete mathematics should cover a wide range of topics, including: 2000 solved problems in discrete mathematics pdf
Prefer official or open-access copies. If a PDF isn’t freely offered by the author/publisher, obtain it through purchase or library loan. 2000 solved problems in discrete mathematics pdf
The content spans the foundational and advanced areas of discrete mathematics:
For completeness, if you just need a simple, non-electronic flap, these are reliable options for those on a tight budget without concerns about strays or prey.
A durable and popular choice for years, the Cat Mate offers simple 4-way locking (in only, out only, open, locked) to control your pet's access. It's a straightforward, no-frills solution that gets the job done reliably without the need for batteries or microchips.