It’s no secret that many of Apple’s products over the last decade have been deeply indebted to the designs of Dieter Rams. Less known, perhaps, is the fact that many of Apple’s apps have borrowed from the master, too. In some cases, like the much-maligned podcast app that lifted its look from the Braun TG 60 tape recorder, the results were unwieldy, to say the least. But in the case of the ET 66 calculator—the inspiration for the iPhone calculator app—the digital facsimile proved just as functional as the plastic product that inspired it.
The classic adding machine, designed by Rams and his longtime design partner Dietrich Lubs, was first released in 1987. It launched a raft of imitators over the years, essentially establishing our collective understanding of a pocket calculator’s perfect form. Its round, convex buttons invited fingers, and its clever use of color distinguished functions from numbers, with the all-important equals button jumping out with a high-contrast, black-on-yellow scheme. A sturdy, hard-plastic slip case has ensured that many original units have survived to this day.
Of course, the design also endured in digital form, on the iPhone’s home screen. Alas, the current version of the iPhone’s calculator app has been tweaked to be something closer to an homage than an out-and-out rip-off—the buttons have morphed into a square chiclet shape, and they’ve been moved around in a place or two—but the understated color scheme is still there.
Whether you use that app or not, it’s almost certain that at some point you’ve encountered a calculator that shows evidence of the ET 66's legacy—one that privileged functionality over flare. Now, once again, you can own the real article.