Horrible app

To remove an app from Outlook, you can follow these steps:

1. In Outlook, go to Home and then select Get Add-ins.
2. On the Add-ins page, select My add-ins.
3. Find the app you want to remove (such as the Dynamics 365 add-in), click on More actions (represented by three dots), and then select Remove.

If you are looking to discontinue a published app from Microsoft AppSource, you can do so by accessing your Microsoft Partner Center account and selecting Stop Selling for the app. After this, you will need to communicate with your customers regarding the uninstallation of the app from their tenants.

If you need further assistance or specific steps for a different app, please provide more details about the app in question.