We have recently updated our apps and we can't migrate passwords for apps as they are encrypted.
If you are having issues logging into your app, if you go to the app website, for example https://classichorrorchannel.com/, there is an "Account" button on the top right corner of the screen that will bring you to a login page that has a "Forgot your password" link. See attached image. Once your password is reset you can use your credentials to log back into the app.