Stop people from embedding my website in their Android App/iOS App/Website?

I searched thoroughly for this and found info on preventing an iFrame, but not an Android or iOS app.

Basically, some blockhead decided to embed my website into his/her Android app and "enhance" it. I assume it's <webview>? (not experienced with Android yet)

Thought about claiming via copyright, but shutting it down via code would be better.

How do I stop them from doing this on an Android app? Is it with JS I can block it or block requests from the app?

Thanks