I use Microsoft Outlook daily in my computer. I really like the power of Outlook for desktop. Now a days Outlook is not only restricted for desktop and laptop users. People can use Outlook in tab and mobile devices also. Microsoft acquired Acompli and re-branded as Outlook for iOS and Android. Acompli was already a good email client for iOS and Android. Microsoft now making it more usable and good quality email client for iOS and Android. They are updating the product frequently with new features and fixes.
I do not use Android. But some of my family members and friends use. Recently I saw updates in Outlook for Android. The shortcut icon changed and become similar to desktop Outlook, we can now create new calendar event invitation from Android and many more new things.
You can read the official post here to know more about the new changes.
Really forward to look for the days when all the Outlook desktop power will come to Outlook mobile and tab.