I previously advocated for a resource tool that showed whether you own a resource that is quoted in a book you are reading. I just discovered that this is easy enough as things are right now. I guess it was one of those "Duh" moments.
When you come to a link in a resource to another Logos resource just hover over the link. If a preview of the resource is given, you own it. If a preview isn't given, you don't own it. This is easier in my opinion then my original suggestion which would require one to take attention away from the resource they are currently reading and thus add a distraction.
I would recommend that hovering over a resource you don't own result in a "You do not own this resource in Logos" message, though. If it has a link to the Logos.com page for that resource, even better :-)