Turning your phone sideways will enlarge the keyboard in all standard applications, including Notes, Messages, Mail, and Safari. This fills the screen and makes it easier to type.
From iOS 8 onwards, and with the release of the larger iPhone 6 Plus, the keyboard has grown larger still. Thanks to the Apple’s larger device, the 5.5 inch screen houses even more options when in landscape position. On top of the audio option, and a handful of grammatical options, the 6 Plus includes buttons for cut and paste, bold, italics and underlined options and more.