Nabla TypeMath is an android application that allow you to easily type mathematical symbols.
Write in any text box, in the form of <initString><Commands><endString> and then press spacebar to convert the commands into unicode symbols.
For example, by default <initString> and <endString> is .. So you can write .x^2 + alpha ^2. , press spacebar and the text will be converted into x² + α²
Most of the commands are similar to LaTeX commands, for example int, in, partial, nabla will all be converted into ∫ , ∈ , ∂ , and ∇ respectively.
More information about the commands is available in the app.