What can you do against copycats who steal your App Icon and your Idea?
Report them via…
https://www.amazon.com/gp/help/reports/infringement
(And hope that Amazon will react)
More:
https://forums.developer.amazon.com/questions/64979/fake-apps-that-steal-your-icon-screenshots-and-tit.html
Sometime I have the feeling, that this world is sick. ;-(