Along with the release of Office suit for iPad, Microsoft announced that the Office mobile is now completely free to use on both iPhone and Android. The change log notes that the apps are free for “home use.” The apps have updated in the respective app stores and now available for download. In addition, update also includes minor bug fixes and stability improvements. 
According to Official Note:
Just like Office Mobile for Windows Phone, we are making Office Mobile for iPhone and Android phones free for everyone. With Office Mobile, you have the ability to view and edit your Office content on the go.
If you’re a home customer, you can both edit and read documents without paying for an Office 365 subscription on iPhone and Android devices. Now, there are free Office apps on Windows Phone, iPhone, Android and Windows RT devices. You can use Office for free, including editing or creating documents, on every device except for the iPad, which requires an Office 365 subscription to unlock editing capabilities.
