The three new Office apps are available separately from the Google Play Store. Word is here; Excel is here; and PowerPoint is here. (OneNote is already available.) These standalone apps, which require Android 4.4 or higher, are the replacement for the Office Mobile hub on Android.
The Office apps for Android phones (and also tablets) are available for free with no Office 365 subscription requirement for those who only want to do light-weight creation, viewing and editing. To unlock more functionality, users need an Office 365 subscription.
Microsoft is pursuing a similar strategy with its Office Universal apps on Windows as it is with Office for iOS and Android. Instead of offering the mobile, touch-first versions of Office apps as a hub, Microsoft is delivering these mobile phone and tablet apps as individual, standalone offerings.