Office Web Apps is a component of the SkyDrive cloud storage service and of the new webmail service Outlook.com. Office Web Apps is also part of the Office 365 cloud-hosted collaboration and messaging suite, which also includes online versions of Exchange, Lync and SharePoint.

This Office Web Apps upgrade, in preview tests since July, is now live on SkyDrive and Outlook.com, Microsoft said Monday. A spokeswoman added that it's being rolled out to Office 365 customers as well, a process expected to be completed by the end of the year.

In addition to the iOS improvements, Office Web Apps has also been tweaked to work better with the final versions of Internet Explorer 10 and Windows 8.

There are also feature improvements in areas such as document authoring, touch interface, collaboration and performance, amounting to what Microsoft in July as the most significant update of the product to date.

Editing, layout and formatting features have been beefed up, while the interface has been optimized for touch-based screens such as those in tablets, following the design of the new Windows 8 interface, formerly called Metro.