Storybook apps are rapidly populating the iTunes store for download onto an iPhone or an iPod Touch. The approach of how to create an ibook for kids varies greatly, depending on the app.

Some create a storybook in which kids interact by touching the illustrations. Others tie touching the illustrations to showing the words in the story, thereby connecting the reading to the pictures. Some completely animate each page of the book but provide no interaction. And others stay true to the static nature of beautifully illustrated storybooks, and simply transfer the illustrated book into an app and then read it out loud.

While the iTunes selection is great, some are not very good. Don't be fooled into thinking that because the story is a classic, like "Little Red Riding Hood," that it is good for little kids. One version by CLT Studio called "iReading — Little Red Riding Hood" is poorly written and frightening. It shows the wolf being cut open and then shot. This is not a story that you would want to share with your 3-year-old, so be sure to preview a story app before you try reading it with your child.

Here's a look at some of the best storybook apps.

"Madera & Figaro in The Rescue of Ginger"

From Lyn And Line LLC, best for ages 3-6, $2.99

This original, 20-page storybook tells the story of Madera (a monkey) and Figaro (a frog) helping Mrs. Applebottom to find her missing cat, Ginger. Madera and Figaro imagine themselves as superheroes as they talk with the animals that live nearby to recreate Ginger's path. This sweet story about helping others uses multiple voices to represent the characters and charming hand-drawn illustrations.

On every page, kids become a part of this interactive story by touching the screen. They will drag acorns into a tree hole to bribe the squirrel to talk and will stack boxes from the biggest to the smallest to help rescue Ginger. In all, there are more than 100 interactive hotspots including activities that teach numbers, colors, shapes and sizes. The cutest ones involve the little mice who, if tapped, dance and do other silly things.

"Little Bella's — I Close My Eyes"

From Tui Studios, best for ages 3-7, 99 cents

This storybook combines little girl Bella's imaginary journeys with short animated videos showing her doing those things. Kids tap on the words to hear her fanciful imaginings read out loud, and then a short movie starts showing Bella acting out her dream.

The animated shorts are breathtaking. In one she imagines being a caterpillar that turns into a butterfly. In others, she turns into a diving dolphin or an astronaut reading a book in space. This storybook is a feast for the imagination and a beautiful canvas for the eyes.

"The Cat in the Hat" — Dr. Seuss

From Oceanhouse Media, best for ages 2-7, $2.99

Lovingly recreated, this Dr. Seuss classic shines as an example of how to transfer a beloved classic book into an app. This version retains all of the original artwork and is read aloud as words highlight on the screen. When you tap on the illustrations, the words from the story zoom over to the object touched, helping kids to make the connection between the words and the objects. The narrator is gifted, particularly when he takes on the voice of the Cat in the Hat.

"1 Little Boy"

From Touchoo, best for ages 2-5, $1.99

This delightful rhyming story can be read aloud by the mesmerizing Aviv Katz or you can choose to record your own voice using an iPhone (this feature isn't available for the iPod Touch).

In this little boy's fantasy journey, he imagines himself going down a road, up to the moon and then back to his room, all the while meeting characters from famous fairytales and rhymes including Puss in Boots, The Cow that Jumped Over the Moon, one of the Three Little Pigs and others.

Each new character joins the boy on the journey and that is where the fun begins. When tapped, each animal makes a sound, and to journey with the boy, the animals need to be tapped into existence by your child. This special feature provides a way for the storybook to count the characters, which also teaches your child to do so too.

"I Can Do It Too!"

From PicPocket Books, best for ages 2-5, $2.99

Karen Baicker's preschool book about a little girl triumphing over daily challenges translates nicely into a digital book app. The girl discovers that she can hold a book like Grandpa and put on clothes like her big sister. Words are highlighted as they're read, and the rich illustrations still look good on the small screen. Sounds make the book seem to come alive.