Microsoft Bookings is a service available to Office 365 Business Premium subscribers who also happen to be small business owners and want to easily manage their staff's schedules, appointment bookings, client reminders, and more. It launched in July in limited capacity and only on the web, with mobile apps promised "in the coming months."
The Android app is now available, but only accessible to beta testers. It's just useful for business owners (clients and staff can use email or the web component) to manage their business from their phone.
They can check their calendar, create or edit bookings, manage their staff's availability, view their customer list and respond to their requests, and get directions to their next appointment if they operate a home service. It's basically every small business owner's dream assistant.
If you're already using Microsoft Bookings on the web, you can head over to this page to sign up for the beta, then grab the free app from the widget below.