Microsoft Office made headlines earlier this summer when it developed an iPhone version of the popular document and presentation-making tool. Office 365 subscribers will be able to download and run an official Office Mobile app for Android off the Google Play Store.

Like the iPhone version, the new app only works on Android-based phones, not tablets. Just like iPad users, Office web apps will have to suffice for those who want to utilize the service on their tablet device. Furthermore, the app only works with a paid subscription to Office 365 and Android 4.0 and above (Ice Cream Sandwich).

Those who subscribe to Office 365 are allowed to run Office on up to five mobile devices, which don't count against the five PCs or Macs that can install the desktop apps. Windows RT and Windows Phone devices don't count against that total either, according to Mashable.

One key difference between the iPhone app and the Android app is that users get the same Word, Excel and PowerPoint programs optimized for the smaller smartphone screen. Once you start editing in a Word Document, the "chrome" of the app's decoration disappears allowing users to focus on just the document.

The default way to save these documents is through SkyDrive, the same way people store things on the iPhone app. However, the app is mostly optimized to look well in the Android operating system as several functionalities adapt to it.

This is a big move for Office and its paid subscription service. While it was a rather unappealing choice on laptops and desktops, bringing it to mobile seems to have been a step in the right direction for Microsoft. Now that market can only expand on the world's number one most popular operating system.

The app, at this time, is only available in the United States, but Microsoft says it will be rolling out the app in dozens of other countries over the next several weeks from Albania to Zimbabwe.