There are 2 different things in play here. You have to consider the capabilities of DVSwitch Mobile (the Android client) and DVSwitch Server.
DVSwitch Mobile can be a IAX client. As a IAX client it can directly communicate with a AllStar node. That node can be AllStarLink or HAMVOIP.
DVSwitch Mobile can also communicate as a USRP client. This is primarily intended to communicate with DVSwitch Server which supports the 5 digital modes.

DVSwitch Server is available as a Raspbian image or can be installed on a existing Debian based system. DVSwitch Server can be installed on a existing AllStarLink node since that node is Debian based.
HAMVOIP is based on Arch, so the DVSwitch Server install packages can not easily be installed on HAMVOIP. ( we are working on a solution to this)

I hope I did not muddy the waters further.
73, Steve N4IRS