I think theducks covers it nicely. Internally an epub is just html (well, xhtml) anyway, so if you need to extract as html that's generally not a problem. Using epub will give you the best chance of finding a variety of tools to help you out and will let you publish to other destinations.
Is it safe to presume that you (michaeltoan016) know that androids can read epub using one of a
large selection of apps?
If you really need to generate an app for direct execution, a quick duckduckgo search for "convert epub to android app" showed a
html to app converter near the top of the list. Further down the results I also found
this epub to app converter.
Caveat emptor! I am not making any recommendations here, I have never used these products, I do not endorse them!
meeera, I presume the idea of creating an app might to let the book be sold and installed directly as an app, rather than as a book to be read by an app. (Different levels of visibility.) I'd like to think it was
not being done this way in order to target 4-6 years for in-app purchasing.
