Via Google Drive Blog: Freeing Quickoffice for everyone.
“Everyone likes free stuff, which is why starting today we’re making Quickoffice available for free, for everyone. With Quickoffice, you can edit Microsoft® Office documents across your devices, giving you the freedom to work with anyone no matter what hardware or software they’re using. Quickoffice also integrates seamlessly with Google Drive storage so you can safely access your files from anywhere. And while the easiest thing to do is simply convert your old files to Google Docs, Sheets and Slides, Quickoffice gives you another way to work with people who haven’t gone Google yet.”
You can get the new, free Quickoffice app for Android and iOS phones and tablets on Google Play and in the App Store.”