Oceanhouse Media on Friday announced the release of three new Dr. Seuss apps for the iPhone, iPod touch and iPad. The Lorax e-book, Lorax Garden Game and Dr. Seuss Senders are now available for $3.99, $2.99 and $2.99 respectively.

Oceanhouse is releasing the three apps to commemorate the 40th anniversary of Earth Day, an event designed to raise awareness of and appreciation for the environment. Earth Day is celebrated in the United States this year on April 22, 2010.

The Lorax, first published in 1971, tells the story a fanciful creature who “speaks for the trees” as an industrial magnate called the Once-ler ravages the environment on a quest to make Thneeds from the foliage of the Truffula Tree.

The e-book developed by Oceanhouse Media runs natively on both iPhone/iPod touch devices and the iPad. Like Oceanhouse’s other Dr. Seuss e-books, it features capabilities developed to promote young children to read, with highlighted pictures and words, narrations and custom background audio.

The Lorax Garden app, created for the iPhone, is a family game that lets players help the Lorax regrow Truffula Tree forests one forest at a time. You can design your own trees and flowers, grow them, then send off digital postcards containing your creations to friends and family by e-mail.

The Dr. Seuss Senders app for iPhone contains 100 digital greeting cards that contain Seussian quotes and sayings ranging from inspirational to cheerful, suitable for messages of love, get-well, congratulations and more, according to the developer. The messages can be saved to your iPhone’s Photo Library or e-mailed.