Make Office Mobile App Free for all Windows 10 Users
Make all the Office Mobile apps work without a Office 365 subscription in Windows 10.
To make it competitive to evil Google.
Ludger A. Rinsche commented
While I don't support the "evil" Google part, I sure think that Office "Mobile", at least Word Mobile, should allow basic editing without an Office 365 subscription.
Just offer as much features as you offer on Office.com, just offline, as sleek and sexy native app. I see Word Mobile as solution for my mother to write a letter every now and then. I see it as an update to WordPad. I see it as the solution for everyone who needs "just some simple word processor" and currently has to use Open Office or something similar (and similar awful).
If you don't want to offer it for free, consider a low-cost one-time payment, maybe 10$.