All Purpose Calculator App for iPad
"The All Purpose Calculator is specifically made to take advantage of the iPad's size and convenience. Controls are laid out to be easy to use with large buttons laid out with the most common functions closest to where your fingers are most comfortable.
The calculator can be used like a standard pocket calculator or in Reverse Polish Notation (RPN) mode.
The calculator can be set for use in right handed or left handed layout.
Unit conversions are quick and easy using the scrolling picker control."
This is a free app