Total Commander - A Shareware file manager for Windows® 95/98/ME/NT/2000/XP/Vista/7, and Windows® 3.1.
Soulver - Soulver is a software application that functions as a calculator that allows you type a continuous stream of information rather than having to input data into multiple cells.
Double Commander - Double Commander is a cross-platform open source file manager with two panels side by side.
Soulver 3 for Mac - A smart notepad with a built in calculator
XYplorer - File Manager for Windows
Numi App - Numi is a beautiful text calculator for Mac.