Microsoft today said that it would flesh out its Office lineup this month by releasing previews of the productivity apps for Windows 10-powered phones.

"The Office Universal apps preview for Windows 10 for phone is expected to be available by the end of the month," said Jared Spataro, the general manager of Office marketing, in a Friday blog.

That preview will follow one for PCs and larger tablets that debuted two months ago. At the time, Microsoft said similar apps for Windows 10-powered smartphones and smaller tablets would be offered "in the coming weeks."

That's now been narrowed to between now and April 30.

Spataro did not list which apps would be included in the first preview of Office for Windows smartphones and small tablets -- the February sneak peak for touch-enabled PCs and larger tablets offered only Excel, PowerPoint and Word -- but screenshots accompanying his blog illustrated the presentation maker and word processor. Images posted by bloggers and reporters who were briefed by Microsoft earlier this week also showed Excel and Outlook Mail, however.

The phone/smaller tablet apps will be similar to those already available for Apple's iOS and Google's Android operating systems. They will also take the place of "Office Hub," an all-in-one-style Windows Phone app for viewing and minor editing of Excel, PowerPoint and Word documents.

What Microsoft will release this month will be the second of two sets of Office for Windows 10 apps: One for smartphones and tablets with screens smaller than 8-in., another for all other touch-enabled devices, including larger tablets, notebooks and desktops, and 2-in-1 hybrids.

Spataro called them "Office Universal apps," a nod to Microsoft's strategy to use a common code base to craft touch-centric apps for devices of all sizes, from smartphones to wide-display all-in-one desktops.

He also used today's blog post to reiterate some of the company's talking points about Office 2016, dubbing the suite's components "Windows Desktop apps," matching the label the company rolled out last month to differentiate between non-touch (Windows desktop applications) and touch (Windows apps).

Microsoft started seeding testers with Office 2016 last month.

Still unclear were details of what Microsoft will charge for its various editions of Office -- whether Office for Windows 10 or Office 2016 on Windows -- and how it will license the mobile apps for commercial purposes.

Today, Microsoft again declined to spell out pricing and licensing. "We'll have more to share when the apps are generally available," a company spokeswoman said in an email reply to questions.

Microsoft's expansion of Office to once-ignored-platforms and the split between touch and non-touch has caused a proliferation of product names that at times is difficult to get straight.

When the firm delivers a preview of Office for Windows smartphones this month it will complete a long list: Office 2016 (for Windows), Office 2016 for Mac, Office for Windows 10 (two editions), Office for iPad, Office for Android tablets, apps for the iPhone and apps for Android smartphones.