Tension Software (http://www.tensionsoftware.com) has updated TS Calc, a Mac OS X document-based application for solving mathematical models, to version 1.3. The upgrade sports an improved layout, a window info panel for any view, and more.
A TS Calc document contains a series of equations and a list of variables and constants used by the equations. When the document is set up, the user can insert the input value and see the output generated by the TS Calc document using the equations to solve the problem.
TS Calc requires Mac OS X 10.8 or higher. It costs US$15.