Specifically, "Starz" (to which I do not subscribe) shows on my screen. But, when I go into "Settings/ Manage Apps" it is not listed.
Please see this help page on how to Uninstall Games & Apps on Your Fire TV Device.
In the future, please note that this forum is for Amazon Developers. You can use the Amazon Digital and Device forum for questions like this.
You can also contact Amazon Customer Service.