The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
From QCD Systems:
This app is designed to stimulate your mind and make you think deep.What we have is a timeless collection of puzzles gathered from a very wide variety of sources which are guaranteed to enthrall you. Some appeared in print in Russian and British books in the early 1900's and some are much older. A veteran would probably know most of these though a few were developed for this collection. And if you can solve all of these without any assistance - you'll beat just about anyone in the IQ department. The collection contains at least one puzzle from each of these - arithmetic, counting, logic, Physics, geometry, graphs and probability. Whether you're a hobbyist or preparing for an interview - you'll find something that will excite you.It's human to be curious and this app challenges you to be just that.