The Math Keyboard is described as 'The ideal keyboard for typing Math and Scientific characters' and is an app in the Education & Reference category. There are three alternatives to The Math Keyboard for iPhone and iPad. The best alternative is Math Keyboard. It's not free, so if you're looking for a free alternative, you could try Nuten — The Math and Science Keyboard or SciKey.
Quickly create equations and share them using your favorite apps. It’s fun and highly educational. You can create and save your equations for later reference. From algebra, geometry, trigonometry and calculus to physics and chemistry, Nuten covers it all.
SciKey is a Scientific Keyboard that brings you the essential scientific characters for your iPad, iPhone, and iPod touch. Fully customizable, with more than 3,000 characters to choose from, to build your perfect keyboard (requires in-app purchase).