Can a Unity apk be added to an existing app?

Hey guys,
I am using Unity to create an AR app, so now I’m wondering if the unity apk can be added to an existing app? or is there a way to build with unity that makes it possible to combine it with an existing app?
I’m keen on unity because i need to get my content from Maya, and Unity seems to be the easiest way to do that.
Thank you for any help in advance
~Steve

I seriously doubt it. Otherwise you could parasite off anyone’s app. If you have your own assets, and there are many AR toolkits, some free, why not just build your own?