A screenshot from the Just Me and My Dad app.

The iPhone is increasingly becoming a popular platform for children’s books. Mercer Mayer’s Little Critter is following Curious George and a handful of lesser-known characters into the Apple App store, getting his own iPhone app. Mayer has published over 150 Little Critter titles in book form with trade publishers. The first Little Critter title to be made available as an iPhone app is Just Me and My Dad, about a camping trip Little Critter takes with his father; it went live in the App Store last week.

Somewhat unusually, this is a case where the rights holder, not the publisher, has developed the app. Mayer and his partner John Sansevere, who run a company called Big Tuna New Media, own the electronic rights to Mayer’s work. In the past, they’ve developed PC versions of this and other Little Critter titles, and the iPhone app is an adaptation of that older version. Like many children’s iPhone book apps, Just Me and My Dad takes advantage of the iPhone and iPod Touch’s touch screen technology to create an experience that does more than the physical book can. There’s animation, sound, and interactivity. Sansevere calls Just Me and My Dad “a cross between an animated book and a storybook. It’s actually reading the words to you, acting out the words, then on every page there are 20 to 25 hot spots where you can touch the screen and it comes alive.”

Sansevere is excited about the potential of the iPhone, saying, “Just Me and My Dad actually works better on the iPhone than it did on the computer, because of the touch screen.” While Sansevere said they’re also working on apps for Android and other platforms, that they’re starting with iPhone because “the iPhone was an open system, it was very accessible to us, and we got tired of listening to everybody talking about it.” Big Tuna New Media is working on seven more Little Critter apps for 2010.