SciKey is described as 'Scientific Keyboard that brings you the essential scientific characters for your iPad, iPhone, and iPod touch' and is an app in the Education & Reference category. There are three alternatives to SciKey for iPhone and iPad. The best alternative is Nuten — The Math and Science Keyboard, which is free. Other great apps like SciKey are The Math Keyboard (Paid) and Math Keyboard (Paid).
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.