Do you remember the story of Mailbox? It was the iOS mail app that allowed you to control your inbox by swiping. Swipe left to archive, right to delete, etc. The approach was a huge hit. In just over a month, Mailbox had a million users and it was purchased by Dropbox for $100 million. And in what may be the greatest seal of approval, the iPhone's own Mail app adopted some of Mailbox’s swipe gestures.
Today, Mailbox is coming to Mac through a beta desktop app. As you might expect, the gestures have come along for the ride. A two-finger swipe right on your trackpad can archive a piece of mail. A swipe left will make it boomerang back to your inbox later. (For those who use a mouse, don't panic—you click and hold to perform all of the same gestures.)
But what you might not expect is that the Mailbox design team considered dozens of other approaches first, going as far as to create functional prototypes. "At the risk of sounding like there's an intuition problem, as a designer, sometimes you have to try things…" explains Mailbox designer Tony DeVincenzi.
I wouldn’t have believed him, had I not seen the renders with my own eyes. One plan turned each piece of email in your inbox into a heat map with big red, green, and brown zones. Depending on where you hovered your cursor on the mail, different functions (like deleting or archiving) would occur—no taps or clicks necessary.
Another approach ditched the heat map, but it stuck the same general functionality into buttons that popped up in each corner of your mail. The solution still wasn't quite right.
"It was really fast," DeVincenzi reminisces. "It also offended a mass majority of the affordances of how a desktop app feels."
Finally, the team circled back to the obvious solution: Make Mailbox every bit as swipe-able as the mobile app. But adding gestures to desktop apps aren’t as casual of a decision as it is for a mobile app. "The basic reason is the lack of direct manipulation as a UI metaphor in OS X and Windows," explains Gentry Underwood, lead designer at Dropbox. While you actually touch buttons on a touch screen, you’re once-removed on a desktop. And while your movements are 1:1 between your hand and interface on a touch screen, the slightest flick of a trackpad can send your cursor across a large screen. "The fact that a desktop has a cursor based UI means it's, on the surface, much more difficult to implement that swipe gesture."
In turn, while building the prototype for the gesture-based Mailbox prototype, they integrated a tool loaded with checkboxes and sliders, enabling them to quickly tweak the resistance and bounce of Mailbox’s animations in order to get the feel just right. "We were making up these weird words, saying, ‘that feels less icey, more spongy!" laughs DeVincenzi. Eventually, the team came to a consensus on the exact physics for each swipe and slide.
The resulting product feels fantastic. In fact, it may be the best trackpad-based gesture system I’ve ever used, outside of Apple’s ingenious two-finger scroll. That said, the Mailbox team actually doesn’t necessarily even want their users deploying all these gestures to manage their mail. Because desktops come with large keyboards, the team deployed a system of "hotkeys" that can handle functions faster than any gesture we know. And users who are used to the different hotkeys used in Outlook will find those work, too.
"The goal is to facilitate as many different ways of working as you can, provided there's not an added complexity to the task," Underwood said. "Keyboard shortcuts, overloading a function with a couple extra keys, these are, there's really no added complexity for the user in that they might enter through all of those places."
Indeed, the new Mailbox is a fantastic illustration of designing a product, not just to be "simple" or to show off gestural polish, but to accommodate users who, at the end of the day, may have preferences beyond mere efficiency.
Mailbox for Mac is unrolling its beta program today.