Apple's first 5.5-inch iPhone, with optical image stabilization and by far the largest battery in the line.
Released September 19, 2014 · Discontinued September 7, 2016 · From $299 (16 GB, with contract)

The 6 Plus was Apple's first large phone, 5.5 inches at 1920x1080 and 401 pixels per inch, the sharpest screen Apple had shipped. It got optical image stabilization the 4.7-inch 6 did not, and a 2915 mAh battery that comfortably outlasted every other iPhone on sale. It also bent. At 7.1mm thick with a long flat aluminum body, a 6 Plus in a tight pocket could take a set, and the coverage ran for weeks. Apple moved the whole line to 7000 series aluminum the following year. iOS 8 added a landscape home screen and two-pane layouts in Mail and Messages for this screen size, which is where the iPad-style split view on iPhone started.
Apple's first large iPhones were read as catching up to Android rather than leading, with the Plus gaining iPad-style landscape layouts.