Here are the latest iPhone/iPod touch/iPod/iPad apps announced. You can find ’em at the Apple App Store (http://www.itunes.com/appstore/).

Open Door Networks and Project A are shipping Earth Envi HD for US$1.99. The iPad-specific app, timed to arrive for the 40th Earth Day, provides access to thousands of web-based photos of planet Earth from outer space. It also includes access to month-by-month climate maps and over a decade’s worth of photos and articles from NASA’s Earth Observatory.

iStoryTime will be giving away select, full featured apps free for Earth Day. The stories that will be available for free this week on the Apple App Store “provide an educational way to inspire awareness and help adults and their children appreciate the environment.”

Wondershare has released Wondershare DVD to iPad Converter and iPad Video Converter. The original price for DVD to iPad Converter/iPad video Converter was $29.95 each; now they’re $19.95. Or you can get ’em bundled for $27.95.

Appigo has unveiled Corckulous for the iPad. It’s a $2.99 idea board in which users can place visually collect, organize, and store ideas.

MobilEaZe has announced iChalk Mobile for iPad 1.0. It’s a $2.99 social drawing app that simulates sidewalk chalk art. Social networking features allow users to share artwork via email, Facebook, or Twitter.

DLdeveloper has rolled out Frog Jig 1.0, a $1.99 jigsaw puzzle experience designed exclusively for the iPad. Designed to take advantage new device’s larger screen, Frog Jig offers a variety of nature photo puzzles and 48, 100 and 225 piece options.

Cornell-Mayo Associates (CMA) says its full suite of back office retail solutions is now available on the iPad, including its Omniexpress point-of-sale (POS) solution, complete with scanner and magnetic stripe reader.

be | daronco has announced Fit Phone 5.0, an update to their $4.99 workout tracking app for iPhone devices. The new version introduces cardio tracking using the built-in GPS unit.

School Zone, which makes children’s educational products, is offering downloadable applications for the iPad. The launch titles, which parents and teachers can download for $9.99 each, are “On-Track Time, Money & Fractions,” “Flash Action Multiplication & Division” and “Flash Action Addition & Subtraction.”

Renkara Media Group has added 32 text-to-speech voices to its $1.99 iPhone/iPod touch translation application, Translate Now!. Male and female voices are now available via In-App Purchase in 13 of the 50 languages supported in the application.

Hunter Research and Technology have released Theodolite 1.3, an update of the free iPhone app. Based on a centuries-old astronomical instrument, Theodolite overlays real-time information about position, altitude, bearing, range, and horizontal/vertical inclination on the iPhone’s live camera image, turning the iPhone into a location-aware viewfinder.

Diethard Seiferth has introduced FirstThings 2.1 for iPhone and iPod touch devices. It’s a $6.99, fourth generation time management app based on the books from Stephen R. Covey and offers weekly planning and challenges for the user to think in roles and weekly goals.

Random Ideas has unveiled iZen Garden 1.1 for the iPad. The update of the $5.99 app features a completely redesigned interface that specifically takes advantage of the iPad’s capabilities. It features over 100 elements that can be placed in your gardens as well as the ability to save and share your creations online.

Vitaliy Pronkin has produced SoundGrid 3.0 for the iPhone and iPod touch. It’s an update of the $4.99 matrix sequencer. Version 3.0 sports a redesigned user interface, web console, live play mode, amp envelope control and more.

DeviceLock (http://www.devicelock.com), which specializes in endpoint data leak prevention software solutions, says the iPhone local synchronization filtering technology built into DeviceLock 6.4.1 controls local data transfers between the iPad and DeviceLock-protected endpoint computers.