Apple reportedly has begun testing a premium iPhone with a revamped display and body, which could be one of three new models the company is expected to launch this fall. The other two likely will be upgrades to the two existing iPhones. The new design will incorporate curved glass and stainless steel. It will increase the surface area of the display without increasing the size of the phone. “The three-phone rumor has been a consistent rumor over time,” observed Kevin Krewell, a principal analyst at Tirias Research.