MathJournal is described as «interactive program for the Tablet PC that provides a natural and intuitive environment for solving mathematical and engineering problems» and is an app in the education & reference category. There are more than 25 alternatives to MathJournal for a variety of platforms, including Windows, Linux, Mac, Online / Web-based and Android. The best alternative is Wolfram Alpha, which is free. Other great apps like MathJournal are GNU Octave, R (programming language), MATLAB and Mathematica.MathJournal alternatives are mainly Calculators but may also be Programming Languages or Statistical Analyzers. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of MathJournal.
