This plugin for the Indigo home automation sever allows you to add thin "adapters" on top of your devices to perform all kinds of mathematical or formatting transformations.

For example, suppose you have devices that report temperatures in Fahrenheit and you prefer Celsius, or the other way around. This plugin can generate "device adapters" that "wrap" around your native device and convert the temperature to the scale you prefer.

It supports all kinds of things: - temperature, distance, and power conversions - arbitrary linear translations of numeric sensors (i.e. multiplier and an offset factor) - custom expressions and formats to transmogrify (single) sensor outputs in almost any way you can think of