What is the BlackBerry Hub+ Notes application, how does it work?

According to the introduction of BlackBerry Limited, BlackBerry Hub+ Notes is a Productivity app on the Android platform. There is currently a 2.1910.0.17488 version released on Dec 02, 2019, you can see the details below.

BlackBerry® Hub+ Notes is a place to keep track of to-do lists, your bucket list, notes for a presentation, or action items from a meeting.
Stay organized by managing all your important notes, from family gift ideas to your weekly shopping list.

Major Features:
• Rich text editor lets you format your notes and organize your lists with bullet points, numbered bullets, and check boxes
• Sync your notes with email providers such as Outlook.com, based on Microsoft Exchange ActiveSync 14.1 or later
• Organize your notes into categories by adding custom tags
• Dark theme option gives your BlackBerry Hub+ Notes a fresh new look and feel
• Fully supports Android Enterprise deployment and, when allowed by your administrator, supports unifying your personal and work notes while maintaining strict data storage separation

BlackBerry Hub+ Notes requires the BlackBerry® Hub+ Services app to deliver a consistent experience across all BlackBerry® applications, and to manage your subscriptions
Enjoy Notes for free on your BlackBerry® device!

If you don't have a BlackBerry device:
• Enjoy full functionality of the app for 30 days
• Purchase a monthly subscription to get full functionality of BlackBerry Hub+ Notes.
This grants you access to all the BlackBerry Hub+ apps, including Calendar, Contacts, Inbox, Tasks, and Launcher.
• Enterprise Customers, please visit: http://web.blackberry.com/forms/enterprise/contact-us
For support, visit docs.blackberry.com/en/apps-for-android/notes/