I am the lead developer at Twixl media where we produce Twixl Publisher.
Twixl Publisher makes it possible to translate InDesign files into iPad apps and this for a great variety of sectors and application domains. Magazines are an obvious application, but Twixl Publisher can also be used for sales presentations, annual reports, newsletters, brand magazines, manuals, brochures, data sheets, and a lot more.
We program in Objective-C, Adobe ExtendScript, Adobe Flex, JavaScript, PHP, Python and plain old bash.