With the release of iBooks 2, Apple is proving that it wants to be the place for interactive books.

Yet for now, when it comes to creating interactive kids books, publishers are often forced to create apps because many features won’t actually work in books sold in the iBookstore.

Digital publishers Ellen Jacob and Kirk Cheyfitz have had to release books as apps to do the things they have wanted to do.

Fast Company has the story: “If you want to sell your book in Apple’s iBookstore, you have to create it on Apple’s iAuthor platform, but then you are only allowed to have video and links in your book (unless those links lead to Amazon’s store, then fuggedaboutit). If you design it so readers can interact with it and have it do all the things that Jacob and Cheyfitz wanted Bats!and Horse Magic to do–both were created on gaming platforms; Bats! on Unity, Horse Magicon Corona–it goes into the app store.”

Not only is this an issue of where a publisher might want to sell and market their books, but it is also an issue of cost. Apps are often cheaper than books, but can be more expensive to produce.