Kindle/Nook type functionality for Joomdle site

We have an app that we would like to use to sell content in a manner similar to the Kindles and Nook apps from Barnes & Noble and Amazon. The current app can be found [login to view URL] We currently use a Joomla site with Moodle for content delivery. We would like the ipad app to integrate with this site. The StudyPad app will be free and come with 1-domain of our workbook, one set of recorded videos for that domain, 1-small quiz, 50 flashcards and one full 250-question practice exam. The app will allow purchase of additional content, and manage user access to purchased content. CLOUD BACKEND This hosts all of the app’s content: workbook, textbook, quizzes, flashcards, practice exams, and videos. Users must pay for content from this site by establishing an account with our site. Each item may be individually downloaded and then managed by the iPad App. STUDYPAD APP The interface has these Buttons Quiz Engine Flash Card Engine Work Book Text Book Recorded Classes Practice Exams Sync Preferences Get Free Content The Quiz Engine button will launch a selection box to select 1 to n canned quizzes. The Flash Card Engine button will launch a selection box to select “all” or a specific domain. The Work Book button will launch a selection box for a specific domain (and just the single domain in the free case): Then allow for the domain content to be downloaded or erased. Load the domain content in a pdf reader if the content was previously downloaded on the device. The last accessed page is book marked and loaded in a subsequent access. The Text Book Engine button will launch a selection box to select a specific domain: Then allow for the domain content to be downloaded or erased. Load the domain content in a pdf reader if the content was previously downloaded on the device. Book mark the last accessed page and load it first on subsequent access to that domain. The Recorded Classes button will launch a selection box to select a specific domain: Then allow for the domain content to be downloaded or erased. Load the domain content in a video player if the content was previously downloaded on the device. Book mark where playback was paused and load it first on subsequent access to that domain. The Practice Exams button will launch a selection box to select 1 to n canned exams. The Sync button will check the cloud for updates to any downloaded content. The preferences button will allow for authentication credentials to be entered/changed for access cloud content. The Get Free Content button will prompt the user for name and valid email address, which is verified, and then provides access to download the free content. An indicator appears if a sync is appropriate each time the app is launched.