360iDev: Lessons from the design of Postage

Developer Chris Parrish hosted a talk this week here at 360iDev in Denver looking back on the development of Postage, RogueSheep's Apple Design Award-winning virtual postcard designer and sharing app for the iPhone. He walked the developers in the crowd through a few of the lessons he and his team learned during development and a few of the principles they stuck by as they built the app.

Parrish said the first principle RogueSheep stuck to was focus. "Cut, cut, and cut some more" was the slide up on the screen. Parrish said that when they set out to make what's basically an image-editing app, there were a lot of things they could have done, like including lots of tools and items to edit images in intricate ways and help users line them up just right. But it turned out that none of that fit the app they were trying to make. Instead, RogueSheep decided to boil the experience down so the user could go from image to postcard to pressing send in just 60 seconds. Parrish called it "putting the user on rails" -- not limiting options, but guiding and rolling users along so the process is as quick and easy as possible.

Instead of the desktop model (which is what the team might have done if it really wanted to create that full tool-based experience), the focus of the app became the postcard itself. Parrish said the team worked to make sure that at every step in the process the postcard was always in view and clearly being built. Instead of moving from screen to screen, the interface slides around the virtual postcard, zooming in and focusing on whatever part of the area the user is working on. Even sending the postcard brings up an envelope instead of going off to some separate email screen, so users are always acutely aware of what they're doing in the app and why.

That email sending feature led to one of the biggest compromises the designers had to make with the application. When it was first introduced, they had to cook up their own solution to send an email with the image directly from the app, a solution which came with its own pros and cons. They were able to use a custom HTML form for the email, but some users -- and their spam filters -- wondered about the email address the message apparently originated from. After the app was released, Apple allowed apps to send email through the OS, and the Postage team eventually decided to create their only preference option: Letting the user decide whether or not to use the custom emailer or the official one. Even that preference was hidden, however. Old users of the app just kept the old feature, while new users got offered the choice. The team wanted to make things as seamless as possible. Parrish said that devs dealing with whether an option should be offered or not should make the best decision they think possible; 80 percent of users will be grateful, even if the other 20 percent would rather have made the other choice.

Parrish also said that whenever you make an app, it's always worth it to go the extra mile on the interface, using custom animations and doing it "right" whenever possible. The team worked for a long time on the "bounce" that the postcard first does when it drops into view, making sure it felt correct and natural. The buttons on the app were sized so they clipped off of the screen in order to inform the user that the button bars were actually scrollable. Parrish encouraged developers to make it look good, blending animations together and making them move in a natural and real way rather than just snapping into place because it's easier to code.

That said, Parrish also recommended making use of Apple's UI classes as much as possible. All of Postage's interface buttons are subclasses of the official UI elements, though they're styled and customized to fit in with the rest of the design. Parrish said that while it's worth working on making things look right, it's not worth writing up your own options only to have them break when Apple changes the system. Use Apple's elements and work hard on the code, said Parrish, but then design it so it works for you and your users.

Parrish's insight was really excellent, and it was great getting a look behind the scenes on Postage's award-winning design.