How do I Block the WordPress App

How do I block contributors and authors from being able to access the back-end of WordPress using the WordPress App?

I run a site that has a large number of authors and I have placed restrictions on authors and contributors so they are not able to make tags or change articles after they are scheduled or published. This works great for the user that access the site through a browser but it all goes out the window for those users that use the WordPress App. They are able to circumvent my restrictions when they use the WordPress App.

I want to make it so that the WordPress App does not work for my site. I have tried to find a solution but have found nothing yet.

Any help on this would be greatly appreciated. Thank you.