Microsoft is launching new and improved versions of its Office software apps for iPhones and iPads, aiming to boost its relevance in today's mobile-driven world.

In addition to the new Office apps for iOS, Microsoft is also working on new versions of its software for Android smartphones and tablets. The Android versions are not yet ready for release, but interested customers can sign up for a preview.

In an increasingly mobile world, Microsoft wants to allow consumers to enjoy the same functionality and capabilities on their mobile devices as they do on desktop PCs. The company has reportedly been working for the past couple of years to develop new web-based versions of its apps and software in order to enable customers to use them even on the smaller screens of mobile devices.

The new updates come completely free of charge and include Word, Excel, and PowerPoint. The apps will replace the limited iPhone Office version that was available until now, and also beef up the set of apps Microsoft released for the iPad back in March.

While the previous iPhone version simply enabled users to view Office files and make only simple edits, the new suite of apps brings the functionality more in line with the iPad versions, offering more capabilities found on Office for desktop.

"Today is the next step in bringing Office to everyone and on every device with the start of Office for Android tablet Preview, new Office for iPhone apps, updated Office for iPad apps and more," Microsoft announced in a company blog post on Thursday, Nov. 6. "The new Office for iPhone apps for Word, Excel and PowerPoint offer the same beautiful iPad experience, optimized for the iPhone."

Moreover, this time the new apps do not require an Office 365 subscription to edit documents or store them in the cloud. On the other hand, while consumers using Office mobile will be able to use the apps for free, Microsoft is not extending the same courtesy to businesses. More specifically, editing documents that are stored on OneDrive for Business or Dropbox for Business will require an Office 365 subscription. This indicates that Microsoft will rely on enterprise to keep its productivity suite and cloud platform profitable. At the same time, some chart element customization and track changes will also be restricted to paid customers only, which means they will only be available as premium features.