As the Apple Watch goes on sale Friday, it's unclear if the gadget and others like it can attain the utility and prominence smartphones have in the past eight years. Ryan Emberley/AP hide caption

itoggle caption Ryan Emberley/AP

The San Francisco-based startup CellScope has built a tool to do ear exams at home, instead of going to the doctor. Cellscope hide caption

itoggle caption Cellscope

A customer sets up her new iPhone 6 at an Apple store in Beijing on Friday. A group says the Chinese government backed an attack against users of Apple's iCloud service, but the government denies the claim. Feng Li/Getty Images hide caption

itoggle caption Feng Li/Getty Images

Apple CEO Tim Cook speaks in Cupertino, Calif., on Tuesday. The company unveiled a new mobile payment system called Apple Pay, which uses security built into the latest iPhones. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

The Samsung Galaxy Mega (from left), Samsung Galaxy S4 and Apple iPhone 5 are shown. Apple is expected to announce larger models of its smartphone on Tuesday. Richard Drew/AP hide caption

itoggle caption Richard Drew/AP

One of the earliest iPhone prototypes. This system was pieced together to test early versions of the iPhone's software. Courtesy of Apple hide caption

itoggle caption Courtesy of Apple

With the ability to control phone calls, texts, and audio, Apple's new CarPlay system will ensure drivers' "eyes and hands stay where they belong," the company says. CarPlay will be included in several car models this year. Apple hide caption

itoggle caption Apple

Apple says it has sold 9 million iPhone 5s and 5c models since their launch on Friday. Here, staff members at an Apple retail store in Beijing cheer a customer after he bought a new iPhone. Andy Wong/AP hide caption

itoggle caption Andy Wong/AP

The new iPhone 5s with fingerprint-unlocking technology is displayed during an Apple product announcement Sept. 10 in Cupertino, Calif. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Apple's fingerprint technology is an effort to combat smartphone theft. Ng Han Guan/AP hide caption

itoggle caption Ng Han Guan/AP