After years of speculation, the Apple Watch is finally here. And though it runs iOS, it has its own user interface, with a home screen bursting with tiny little bubbles, each one of which represents an app. Why circular icons when Apple uses rounded squares for iPhone and iPad icons? Probably because they're more ergonomic for prodding on a tiny smartwatch screen. Circles are a simple way to make information both legible and accessible with limited real estate.
They also represent the strategic value of flat design. Flat design is a minimalist design principle in which any design flourish that gives the illusion of three-dimensions--shadows, gradients, textures, and so on--are stripped away. It's in vogue right now because it allows designs created for one medium, like digital, to more easily make the transition to entirely different platforms, like print. Or, in the case of iOS, transition from smartphone to your smartwatch.
Last year, I wrote that flat design was paving the way for the iOS devices of tomorrow. In it, I argued that iOS 7 embracing flat design wasn't just about a new aesthetic: by eliminating gradients and skeuomorphism, Apple was creating a design language that could be adapted to many different screen sizes and shapes.
At the time, I wrote:
Think about how easy this makes Apple's job, adapting their visual language to new devices. If Apple ever releases their long-rumored HDTV, it will likely feature large icons that can be seen across the room. But Apple won't have to create entirely new icons or art for this new user interface: instead, flat design allows them to easily (and even automatically) expand their existing icons to fit any shape they want. If Apple hadn't redesigned iOS 7 to be flat, this would be impossible. Icons would have complicated patterns, shadows, light sources, and gradients that would need to be reinterpreted and recreated for each new device. But because iOS 7 was designed to be flat, none of this is a problem.
There's another benefit here, too. Right now, all displays are flat, but in the future, displays will come in all shapes, sizes, and contours. Samsung has already unveiled the Samsung Galaxy Round, the world's first smartphone with a curved OLED display, and the iWatch is similarly widely rumored to curved. Skeuomorphism tends to look strange on curved displays, like seeing something in a funhouse mirror, but flat designs don't distort in the same way. Ironically, by going flat with their UI, Apple has prepared itself to eventually go 3-D with its displays.
The Apple Watch doesn't have a 3-D display yet (it's disappointingly flat, unlike smartwatches such as the Moto 360 and the LG G Watch R) but Jony Ive's redesign of iOS a year ago has made the Apple Watch possible.
Flat design was the iWatch's secret weapon all along. And beyond the Apple Watch, flat design also paves the way to new Apple products we've scarcely even begun to dream about.