I use the siddur, Tana"ch and Mishna apps from JewishContent.org. They aren't that simple to install and they sure ain't pretty – fonts aren't too smooth. But it's the words that come out of your mouth that matter, right?
Unfortunately, there doesn't seem to be much that I could find for the Playbook. You would think with such an awesome screen, a nice crisp PDF would be great to use. Even better, an EPUB or Kindle siddur (chumash, etc why not) with a navigatable Table of Contents. But I haven't found that yet. I do use the PDFs from HebrewBooks.org for gemara. You can find some pretty simple PDFs for davening at http://www.mincha.com