Today Microsoft revealed iPad versions of their popular Office products: Word, Excel, and Powerpoint.  All three are free to download and view documents, but if you want to edit anything you need to pay for the Office 365 subscription of $10/month or $99/year.

CEO Satya Nadella promised Microsoft is going to be pushing Office 365 subscriptions across all their platforms.  This means that even on Windows you won't be able to escape subscribing if you want to use new versions.

Source: [url]thenextweb.com/microsoft/2014/03/27/microsoft-unveils-office-ipad/[/url]

If you don't need Microsoft Office specifically, Apple's offerings: Pages, Numbers, and Keynote, are all free on iOS.