Are you trying to use the same login information the you use for your ZonGuru account for the web? If so, you actually need to quickly create a fresh account to use the mobile app (you can use the same login information that you use for the web platform if you would like). Once you create an account on the mobile app you shouldn’t have any issues logging in.
Also, once you pay for the mobile app in the app store you won’t need to pay anything else to create an account and use the mobile app.
It’s important to note that the mobile app and the web platform operate independently from one another - so just because you have an account online does not mean you’ll be able to login to the mobile app with that login info. Think of the ZonGuru mobile app as all your relevant sales data organized and easy to check at the palm of your hand. Whereas, the web platform delivers a suite of tools to help streamline and automate your Amazon business.
If you are still having issues logging in please contact us at firstname.lastname@example.org