You don’t want users of that device to have access to anything other than that single app, because it’s not necessary. For such use cases, you can effectively create a kiosk – a user account that has access to only one Windows Store app.

To do this, you first need to set up a secondary user account on the computer (you can’t do this with the main admin account for, hopefully, obvious reasons). Ignore Microsoft’s attempts to create a Microsoft account for your new user and click on the options that say “I don’t have this person’s sign-in information” and “Add a user without a Microsoft account” in the user setup wizard. You might not even bother with a password on this account, as it’s only going to have access to a single app.

Once the new user account is set up, go back into the admin’s account and type “assigned access” into the Windows 10 search bar and click on the option for “Choose an account for assigned access”.

Choose the account you’ve just set up and then choose the app that account can access. Note that the app must already be provisioned for the account you’re using. So, if you want to provision an app that’s not one of the core Windows apps, download it afresh from the Windows Store on the new user’s account.

As of October’s Windows 10 update, you can also assign the Edge browser as a kiosk app. One example case is to provide an internet kiosk in reception, for getting guests to sign in via a page on the company’s intranet.

Microsoft has a special page dedicated to deploying Edge in a kiosk scenario, which is worth reading.

Note that, when you want to exit the kiosk account, you must use Ctrl+Alt+Del because the account doesn’t have access to the Start menu and its various power/login options.