Microsoft may be building a lightweight email app called Flow

Microsoft's Outlook for iOS may be getting some company, in the form of an app for fast, lightweight conversations called Flow.Josh Miller/CNET

Microsoft seems to be developing a new application designed to enable "rapid email conversations on your phone with the people who are important to you."

That new application, called Flow, is meant to be an adjunct to Microsoft's Outlook email client, according to a download page for the new app, marked "Microsoft Confidential." The page was discovered by @h0x0d on Twitter.

The header of the download page calls the app "Flow by Outlook" and indicates the coming app will be available for Apple's iPhones. The text describing the app:

Use Flow with anyone, it's email: Reach anyone with an email address and all conversations for you and others are also in Outlook. Together, you can use Flow and Outlook interchangeably to participate in the same conversations.

Fast, fluid, natural conversations: No subject lines, salutations, or signatures. Flow is designed for fast, light-weight conversations in real time.

Focus on what's important: Only conversations started in Flow and their replies show up in Flow, not your whole inbox. Focus on your most important person-to-person conversations without the noise.

Flow sounds in some ways like the email complement to Skype Qik. Skype Qik, a video chat app for Android, iOS and Windows Phone devices that Microsoft made available last year, was designed to be "as lightweight and convenient as SMS and IM," according to Microsoft. All that was required to communicate via Qik is a mobile phone number.

Microsoft's Outlook for iOS app is a rebranded version of the Acompli email application Microsoft bought at the end of last year. Outlook for Android is, likewise, the Microsoft-rebranded and updated version of Acompli. Microsoft's new Outlook app for Windows Phones, currently in preview for Windows 10 Mobile, looks similar to these other two versions of Outlook, but isn't based on that same code base.

The Outlook, Outlook.com and Exchange teams are all part of the same group at Microsoft under Corporate Vice President Rajesh Jha.

I asked Microsoft officials for more information about Flow, including details such as when Microsoft plans to make it available for iOS (and other platforms) and who the target audience is. A spokesperson said the company had nothing to share about Flow.