The Fourth Dimension is a 30-page interactive book that explains a single mathematical idea in language that anyone can understand. Instead of static images or canned videos, this app employs a unique 3D touch interface that lets you literally grasp the concept of the fourth dimension with your own hands.
Important: All the freebies mentioned here are free at the time of publishing this article. It may, you see some price tag instead of “Free” when visiting the store which means the product is no longer available as “Free”. Not being free and you buy or download it, you may be charged with the price of the product. Please, also be aware that some apps may have in-app-purchases options.