Calcbot is an intelligent unit converter and calculator that comes with multiple features, such as history tape, intuitive conversion, and expression view. Every calculation done gets recorded in the history tape and your clipboard for easy and quick pasting. The original expression view lets you see all things you typed, thereby ensuring you do not miss a typo or forget things you entered. There are more than 500 units spread across 22 unique categories, which includes currency rates that update automatically.