If the "App not found" error message blocks your attempt at downloading the ScreenCloud player app from your Amazon app store, the issue can be resolved by changing your Amazon account setup.
You will need to make sure your Amazon account is set up with the Full Experience option, and not the Basic option. The Basic option limits the apps you can use to only streaming and live TV apps, which does not allow you to install the ScreenCloud player app.
Please find more information on Amazon's What Are the Basic and Full Experiences on Fire TV Smart TVs? support page.
If you continue to see the issue even after performing the above steps, please reach out to our support team, as we will be happy to help.
Reference:
https://www.amazon.com/gp/help/customer/display.html?nodeId=GQKNUYZEFWJ6D5QY
You can find help here on how to resolve the “App not found” issue for your Amazon Fire TV device
Updated over a month ago