Microsoft is launching a new version of its Outlook mobile app for iOS today. While big app updates usually involve a lot of new features, Microsoft is taking a different approach as this is nearly all about design. There are subtle changes here and there that are designed to polish up the Outlook for iOS experience. The calendar icon animates when you’re moving backwards and forwards, and swiping to take actions on emails now includes haptic feedback so it feels like you’re moving an email. While you might not immediately notice these changes, there’s one very obvious and blue addition at the top of the app.

“The blue was not there [on iOS],” says Miles Fitzgerald, who leads the mobile design for Outlook. “We’re bringing the family together, and we’re proud of our brand.” The blue was part of Android, but this latest design is clearly a bigger effort to move away from the all white design of Outlook for iOS that originally shipped as an app to compete with Apple’s built-in mail app. Microsoft originally acquired its Outlook for iOS app when it was Accompli four years ago, and it now has more than 100 million users across Android and iOS. Microsoft is also working on a dark mode for Outlook mobile, and it’s a highly requested feature. That dark mode won’t debut today, but it’s something that will appear in a future update.

The design changes also extend to just making things quicker and easier to use. You’ll now get prompted to setup custom swipes if you go to use that feature, and there’s favorite folders to make mail management a little quicker. Microsoft has also included avatars within the inbox, so it’s easy to glance at your messages and see who they’re from. Even responding to calendar invites has been improved, simply by adding an inline view of your calendar when you’re about to hit accept or deny. Search now includes recent people and queries, just to make finding things a little more convenient.

All of these little changes add up, even if people don’t even immediately notice them. “We do a lot of research and understanding if it actually increases positive feelings for the product,” explains Jon Friedman, who leads Microsoft’s design efforts for Office. “What we’ve found is that if people have more positive feelings towards a product, which is different than just how they rationally think about it, there’s a correlation to higher net promoter score, higher retention, and longer life time value of that people using the app.”

Obsessing over the details, animations, and just the joy of using an app is something we don’t always see from Microsoft. It sounds like this is part of a far bigger design effort at Microsoft that goes beyond Outlook for mobile, as Friedman reveals in an interview with The Verge. This latest Outlook for iOS design will go live in Apple’s App Store today, and you can update immediately to try out the new changes.