To build an App, I took the same minimalist approach. I saved a copy of my Wordpress blog post, zipped the resulting files, uploaded them to Adobe PhoneGap and generated an Android App called "Mobilize Education". The only tricky part was that I had to rename the web page "index.html". Phonegap asks for a
config.xmlfile, as per the W3C widget specification, but this is not essential in this case, as the "App" is just a web page.
The files for the web pages are 194 kbytes when Zipped (654 kbytes uncompressed). The App is considerably larger at 1.1 Mbytes, but I expect this is for programs and as more content was added the overhead would be a smaller proportion.
It looks to me that it would be very easy to take content from a Moodle eBook, ePub, Kindle, SCORM or any of the other web based content formats and turn it into an App (these all consist of zipped web pages). Of course if you wanted a more interactive App, that would take more work.
ps: The App is also available for Windows Mobile, but who has that?