Well, this is a surprise. Microsoft today released native Outlook clients for iPhone and iPad, providing users of those mobile devices with native apps for Office 365-based email, contacts and calendars. Called OWA (which actually stands for Outlook Web App), the new apps require an Office 365 business subscription.

“Our goal is to help our customers remain productive anytime, anywhere,” Microsoft’s Andy O'Donald writes in a post to the Office 365 Technology blog.  “This includes providing a great email experience on smartphones and tablets.  Windows Phone 8 comes with a top-notch native email client in Outlook Mobile, and we offer Exchange ActiveSync (EAS), which is the de-facto industry standard for accessing Exchange email on mobile devices.  In order to better support many of our customers who use their iPhones and iPads for work, we are introducing OWA for iPhone and OWA for iPad, which bring a native Outlook Web App experience to iOS devices.”

(The iPhone version of the app also worked on iPod touch.)

If you’re familiar with the “Metro” design of Windows Phone apps or the Outlook.com mobile app for Android, the look and feel of OWA for iPhone and iPad will be immediately familiar, with large, clearly read fonts and a nice (if unlike iOS) look and feel.

There are some unique bits. The app requires you to create an in-app PIN in order to access your Office 365 information. On EAS-based systems, Office 365 can of course simply require that you use a PIN to unlock your device, but I guess the app can’t check for that.

There’s a unique Navigation button in the left of the app bar. Tap it and you get a handy tile-based menu for accessing your Office 365 mail, people (contacts), and calendar, as well as options.

Tap and hold that Navigation button and you can access a Windows Phone-like speech interface that lets you trigger new emails, opening the calendar and other Outlook tasks. In my admittedly short bit of testing, this was slow and didn’t work very well.

I only tested the app on an iPod touch, but Microsoft’s own screenshots (which I'm using here) show that the different versions of the app are tailored for the unique device types. So while the email inbox view on iPhone/iPod touch looks and works much like the Mail app in Windows Phone, the same view on iPad provides two panes, one for messages and one for the currently selected message, and it looks and works more like the actual web-based OWA.

According to Microsoft, the OWA apps for iOS work with IRM (Information Rights Management, the new Apps for Outlook, and remote wipe, so that admins can silently remove internal data from stolen or lost devices. And because they’re native apps, they of course work offline, unlike the web-based OWA. I’m not an iOS user, but these apps look pretty impressive.

Download OWA for iPhone (requires iPhone 4 or newer)

Download OWA for iPad (requires iPad 2 or newer)