All officeatwork 365 apps and Add-Ins for Office 365 are govern by the Terms and Conditions listed for each App or Add-In in the Office Store (appsource.com).
Installation and Use. If you are provided with an App or Add-in by officeatwork AG directly (not by the Office Store) you may install and use one copy of the application on up to five (5) devices you personally own or control and that are affiliated with your personal Microsoft Account or your Office 365 subscription. You may not install or use a copy of the application on a device you do not own or control.
Competitors that offer competing solutions for any Office product like Microsoft Office are explicitly excluded the right of viewing or using any content or service/software provided by officeatwork.