Haiku Deck - Haiku Deck has always been free. But, there are in-app purchases that normally cost $1.99 each. Right now, certain ones are free, but get them quickly. The themes titled: Lucha, Orwell, Strangelove, and Underdog. I would check each theme to be certain that the others didn't go free. Regardless of getting these themes or not, Haiku Deck is a must have app for presenting with great visuals and forces slides to become succinct. This app is constantly improving and recently they released a presentation remote associated with the iPhone app. So, download this one and try to find the free themes.
Publisher Star (notes, flyers, scrapbooks pages,etc) - At first glance, this apps was fairly easy to understand. When opening the app for the first time, there are a few example projects to manipulate and publish with several choices.
4 Dice a Fractions Game - This looks like an interesting collaborative app, and I would like to see this game played with students. The one thing I didn't like is the Facebook connection within this app. Too often, iPad games that would be great for kids have a Facebook connection, and promoting a Facebook connection in class just isn't an option (or risk) that many teachers want take.
Storyteller Deluxe - It's not a pretty app. In fact, as I was playing with it, the top portion of the screen was partially blocked by the bar indicating my wireless signal. However, this apps seems to get the job done when creating a digital story. Students can add text, audio, images, and share their final products.
PICSMART for Sped. On Sale for 9.99 normally 99.99 - This would be a great app for parents or teachers that work with children that need help communicating their needs or feelings verbally.