NOTICE: At present, the master branch will only be a text file until I can figure out how to include all of the versions in one package.
As of the time of this writing, the current version is 5.3.1, and setup is relatively straightforward: cordova plugin add https://github.com/agamemnus/cordova-plugin-xapkreader#5.3.1.
There is also a Cordova 5.0 version (because of the somewhat difficult bugs with it, it's not trivial to set it up correctly): cordova plugin add https://github.com/agamemnus/cordova-plugin-xapkreader#5.0.
If you need a Cordova pre-gradle version (which is I think Cordova 3.6?), use the pre-gradle branch: cordova plugin add https://github.com/agamemnus/cordova-plugin-xapkreader#pre-gradle.