When it comes to the number of apps available on both Android and iOS platforms, they are solidly in the hundreds of thousands, although some might argue that not all of these apps are beneficial in any way, being crapware or bloatware. However, there is a fair number of decent and even pivotal apps on both mobile operating systems, and Microsoft does not want to miss the boat with Microsoft Office for iOS and Android.
It seems that Microsoft is working on launching this new app sometime at the beginning of next year, where the apps will allow you to view documents using a free Microsoft account. However, should you want to edit the apps, you are required to sign up for an Office 365 subscription. I guess you can call it Microsoft Office Lite, but at least they enable you to perform some of the more basic edits while you are on the move. Microsoft Office for iOS should arrive sometime in February or March next year, with the Android app to follow a few months after that.