With the recent advances in the programmability and performance of mobile Graphics Processing Units (GPUs), General-Purpose Graphics Processing Unit (GPGPU) technologies have become available even in mobile devices such as smartphones and tablets. Among the available GPGPU technologies for mobile devices, Open Computing Language (OpenCL) and RenderScript are used to accelerate applications in various fields such as computer graphics, image processing/recognition, and computer vision. For example, these technologies are used for detecting collisions and edges, processing data from a camera, recognizing an object in an image, processing the images stored on a device, and accelerating the drawing of an image when live wallpaper is used in Android-based devices. These technologies increase the processing speed as well as reduce the power consumption of mobile devices. In addition to these general applications, they have great potential for use in the optimizing algorithms of scientific fields. This paper describes GPGPU technologies for mobile devices, compares their similarities and differences, and compares their performance for further research purposes. To the best of our knowledge, this paper is the first work that compares and analyzes available GPGPU technologies for mobile devices.