Simple Pint

Simple-Pint provides a simple means to convert from pints and fluid ounces to litres or millilitres by sliding a finger across the iPhone screen. Both US Customary and UK Imperial measures are supported. The display separately shows the ounces and pints values; touching either sets the slide to increment in units of that value, changing the metric display accordingly, in a large, easy to read font. Touch the metric display to increment in metric units.
Slide a finger across the ounces or metric value to increase or decrease the number of decimal places displayed.
The sensitivity of the slide - how much the units increase (or decrease) with a given slide length - can be controlled through the properties of the app.
Rotating the iPhone provides different interfaces for left- and right-handed users; double tapping the slide-area resets the displayed value to zero.

Simple-Pint: the simplest route from imperial or customary to metric measures.