Surprising development of the day: Microsoft just made Microsoft Office free on iOS and Android:

Microsoft’s Office suite for iPad, iPhone, and Android is now free. In a surprise move, the software giant is shaking up its mobile Office strategy to keep consumers hooked to Word, Excel, and PowerPoint documents. Starting today, you’ll no longer need an Office 365 subscription to edit documents or store them in the cloud.

If nothing else, this answers the question of “What’s more important to Satya Nadella’s Microsoft: Office or Windows? The answer is very clearly: Office.

Essentially, unless you’re an advanced user, you no longer need an Office 365 subscription to use Office on iOS or Android. All the basic editing’s right there, and you can share files using Dropbox, which it now supports. Windows might be a very distant third in the mobile space – but Microsoft is clearly determined not to let the same happen to Office.

This might just have given the shift to mobile another boost – as if it really needed one – in taking away another obstacle for many users in shifting away from the desktop computer. If your Office documents can come with you, it all gets much easier…