Legal clarifications

Thank you Canon for your responses.

If I create an interactive app for a client it is supposed they’ll use it to show to their clients (let’s say an architectural walkthrough or a reconstruction of an ancient building for a museum), not to put it in a digital market like Google play or similar. This way would’nt pay royalties, right?

Let’s suppose I create ten applications … I won’t be able to track all of them all the time to see if the client is using them in a way they don’t break your Eula … as I told you, I’m a freelance and this would be difficult for me and I think it is not fair I’m responsible for the bad use others can make of the product. Is there a way I can protect myself of this possible situations? I also don’t know what it means for the client to become a licensee of Epic, can you explain it a bit, please?

thanks again