MathType

APA:

"We strongly encourage you to use MathType (third-party software) or Equation Editor 3.0 (built into pre-2007 versions of Word) to construct your equations, rather than the equation support that is built into Word 2007 and Word 2010. "

cf.

APA: Manuscript Preparation

http://www.apa.org/pubs/authors/instructions.aspx

 

MathType