For any BlackBerry 10 die hards still using the Office Mobile app, Microsoft has announced that they are retiring Office support for all versions of KitKat and Lollipop at the end of this month.
The Office mobile apps for Android, will be ending support for Android 4.x (KitKat) and 5.x (Lollipop) on June 30, 2019. Starting on this date, users with devices running on KitKat, Lollipop or older versions of Android will stop receiving app updates. We recommend that your users upgrade to a newer version of Android.
Note: Outlook for Android will continue to support Android KitKat 5.x (Lollipop) until December 31, 2019. After this date, if you are using a device running an older version of Android, you can access your email and calendar by using the mobile web version of Outlook.
[How does this affect me?]
Users who do not upgrade Android in their devices will be able to continue using the Office apps with limited reliability but will not receive any feature or security updates. If they delete the apps they won't be able to download them again until they update their device to a newer Android version.
[What do I need to do to prepare for this change?]
We recommend that users upgrade their version of Android or access email and calendar using the mobile web version of Outlook.