Originally Posted by matt bernius
Along these lines, is it possible to "sideload" a book purchased from Kobo into aa different android e-reading app?
Yes, if you download the "other" ePUB version. The Kobo native format (which is also an ePUB, but with Kobo's own proprietary DRM) can only be read on a Kobo device or app. Folks with Android devices (like the Vox for example) are sometimes using Aldiko, Mentano, etc. for some books.