there are several (11)forums that I follow as a guest and I don't experience that prompt issue at all. It did prompt the first time I visited the forum, but after that no more prompts. Perhaps there is a setting on a particular forum you visit?
I love tapatalk, it makes visiting and interacting in online forums possible on my phone - I can't stand using them with a mobile web browser. There are features missing on a lot of web interfaces that tapatalk enables. For instance, quickly being able to go to the threads you have participated in without needing to subscribe to them.
When I purchased tapatalk, I searched for LRO first and it wasn't there..
I don't think a license would need to be purchased, unless LRO wants to have an app developed.