Ever since Susan Kare’s 8-bit designs graced the first Macintosh screens in 1984, icon design, like digital typography, has been an important if unglamorous niche in the software business. The 2008 debut of Apple’s App Store created “a sea change in our industry,” says Gedeon Maheux, co-founder of Iconfactory, a large design studio in Greensboro, N.C., that does work for big brands such as Windows and Twitter. “It gave us job security.” A decade ago, one of Iconfactory’s principal designers specialized in mimicking the large-format, heavily detailed visual style of Aqua, Apple’s name for the user interface on its Mac OS X operating system. (Aqua’s environment was designed to conjure water, from bubbles to the way light is refracted undersea. “We made the buttons on the screen look so good you’ll want to lick them,” Steve Jobs told an interviewer.) Now Iconfactory also designs custom emojis the size of cookie crumbs. Icons and glyphs—the term for symbols that blur the line between typography and pictograms, such as the triangular “play” button on online videos—must be drawn for every screen size that Silicon Valley produces, from 5K resolution monitors to smart appliances and wearables. Designers such as Maheux and Mantia, who also was at the Iconfactory before starting Parakeet, are the ones doing that work.