Numi App - Numi is a beautiful text calculator for Mac.

MathType - The Professional version of Equation Editor- MathType is a powerful interactive tool for Windows and Macintosh that lets you create mathematical notation for word processing, web pages, desktop publishing, presentations, and for TeX, LaTeX, and Math…

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.

Math Magic - MathMagic Equation Editor for Desktop Publishing software & Word Processors, Adobe InDesign, QuarkXPress, MS Word, iWork, for Technical writing with very easy interface and fast input.

Parsify Desktop - Extendable calculator for the 21st century ⚡

MathCast - MathCast is an equation editor, an application that allows you to input mathematical equations.