Frank Shaw, head of communications at Microsoft, tweeted this:
Home screens everywhere, unite! Msft apps/services being used/loved by people wherever they are, on all their devices pic.twitter.com/QkM4Xu2Exb
— Frank X. Shaw (@fxshaw) February 12, 2015
I do see that the individual Office apps are running on an Android phone. This would be an update to the current Office Mobile, and would be the same as iOS and Windows Phone 10 (at launch).
…and then when you open the Sunrise app on Android you are greeted with this image: