My Drivers, a Chinese website covering the IT industry, reports that Apple's higher-end iPhone this year will be call the 'iPhone 7 Pro'. This name change will be do to the exclusive features found in the model, which would be different from the 4.7-inch and the standard 5.5-inch iPhones.
Currently the only exclusive feature that has been rumored for the Pro model would be the dual-lens system. If this holds true, Apple would be releasing three different smartphone models in the Fall: the 4.7-inch iPhone 7, 5.5-inch iPhone 7 Plus, and a 5.5-inch iPhone 7 Pro.