I've checked my iTunes folder on my Windows computer. There's ...iTunes\Mobile Applications\ which contains all apps' *.ipa files. I took a peek into one of them (i.e. added .zip extension and opened in Total Commander ), but wasn't able to find any "content files" there (e.g. no PDF or RTF files in GoodReader), just the app. So when I synchronize or backup apps from my iPad to my desktop computer, where does the content go?