That 4-inch screen on your iPhone 5 is nice for watching movies or playing games. However, it can be a major pain to type on it. Most of that has to do with Apple’s tiny built-in keyboard.
Big Finger Keyboard can come in handy. It gives you bigger buttons that you can tap in multiple places to generate different letters. Fewer buttons means each one is easier to hit for fewer mistakes.
Note: Apple does not let you change the default keyboard in iOS. To use this keyboard, you must load the app every time you want to type.