Building a site collection from a sharepoint app?

Is there any way to build a site collection from a SharePoint 2013 app? Or is it still best to use wsp files for web templates?

We have a site collection we would like to add licensing to; it's easy to deploy a site collection from a wsp file, but not so easy to add licensing to that wsp file. On the other hand, it's easy to add licensing to a SharePoint app, but I can't see any straightforward way to build a site collection in a SharePoint app.

Any insight/suggestions? Thanks!!