Typing
Smartphones have built-in and built-on keyboards (for touch screen interfaces) for things like typing emails, notes and websites. But the keyboard is significantly smaller on the smartphone interface than it is on a computer and characters are packed closely together, all of which limits how fast you can type. What's more is that you're often only typing with a single hand, as one hand needs to support the phone, which can lead to stress and overuse injuries in your typing hand. Additionally, you have to access different versions of the keyboard for special characters and numerals, which also impedes the speed of your typing.