PsychoPy is described as 'open source software package, written in Python programming language, for the generation of experiments for neuroscience and experimental psychology' and is a Presentation Maker in the Office & Productivity category. There are four alternatives to PsychoPy for Windows, Mac, Android, Android Tablet and Linux. The best alternative is OpenSesame, which is both free and Open Source. Other great apps like PsychoPy are DMDX (Free), Paradigm (Paid) and SuperLab (Paid).
OpenSesame is a graphical, open-source experiment builder for the social sciences. It sports a modern and intuitive user interface that allows you to build complex experiments with a minimum of effort.
DMDX is a Win 32-based display system used in psychological laboratories around the world to measure reaction times to visual and auditory stimuli. It was programmed by Jonathan Forster at the University of Arizona.
SuperLab 4 is the stimulus presentation software for Mac OS X (10.4 or later) and Windows 7/Vista/XP. In development for almost five years, the new SuperLab 4 introduces a host of new features, including: