Math Minion is described as 'started out as a powerful scientific calculator and modelling system with a deep understanding of conversion units, but over time it has evolved into much more. When string handling was introduced to its powerful array handling, it became an adept string processor' and is an app in the Education & Reference category. There are more than 10 alternatives to Math Minion for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and Self-Hosted solutions. The best alternative is LibreOffice - Math, which is both free and Open Source. Other great apps like Math Minion are MathType (Paid), KLatexFormula (Free, Open Source), EqualX (Free, Open Source) and Apache OpenOffice Math (Free, Open Source).
Math is the LibreOffice suite's formula editor, that can be invoked in your text documents, spreadsheets, presentations and drawings, to enable you to insert perfectly-formatted mathematical and scientific formulas.
MathType is a powerful interactive equation editor for Windows and Macintosh that lets you create mathematical notation for word processing, web pages, desktop publishing, presentations, elearning, and for TeX, LaTeX, and MathML documents.
Math, part of the Apache OpenOffice suite, is a tool for creating and editing mathematical equations, similar to Microsoft Equation Editor (included in Microsoft Office). The created equations can then be embedded inside other OpenOffice.
LaTeXiT is a small utility that allows you to quickly typeset LaTeX equations, without bothering with file creation, preambles, and so on. The PDF image obtained can then be exported by dragn drop to any application supporting it.
Tex2Img is a free online Latex equation editor that converts Latex equations to high resolution images to embed in documents and presentations. You can also use Tex2Img to learn Latex by trial and error.