Knob is a rotary web UI element that can be controlled by dragging and rotating it with the mouse pointer or touch input. It allows you to choose a value by dragging a pointer inside a circle. Knobs are extremely useful when you need some new functionality in your app. Many mobile apps utilize this piece of UI for many different reasons. And there are plenty of examples on Dribbble which express enormous bouts of creativity. So in this post I’ve collected some awesome UI designs inspired by a control knob, such as those found on a mixer.