In memory of Dr. Seuss, who celebrated his birthday on March 2nd, Oceanhouse Media and Dr. Seuss Enterprises is running its annual sale on the author’s apps.

Featured sale apps include The Cat in the Hat digital book app which is on sale for $.99 down $3 from the app’s regular price $3.99 price tag. In addition, The Dr. Seuss camera app is available for free. The promotion includes discounts on more than 40 Dr. Seuss apps. The sale runs through March 7 and is good across platforms including the App Store, Google Play, Amazon’s Appstore, Nook and Windows.

In addition, the two companies are participating in The National Education Association’s Read Across America Day, an annual reading program that encourages adults to read to children.