Microsoft has developed an Administrator app for your mobile devices that allows for the management of your 365 accounts. The app is currently available on both the Apple Store and Google Play. 

     The App is feature packed with over 80 total features that makes it possible to manage your organization on the road. Some of the things you are able to do with the app includes adding new users, creating or deleting group memberships, management of licenses, and resetting users passwords. Most important of these features is the ability to request support and view past and current Office 365 service requests. For users who manage more than one organization it possible to log into each organization and switch between them easily. 

The app can be found at the following links:

For Apple visit https://apps.apple.com/us/app/microsoft-365-admin/id761397963

For the Google Play Store visit https://play.google.com/store/apps/details?id=com.ms.office365admin&hl=en_US

More information is available from directly about the Office 365 Admin app is available from Microsoft here.