Google Play and other 69,000 icons from Icons8 icon pack follow the visual guidelines of the operating systems: Windows, iOS, Android KitKat, and Material. PNG format is free up to 100x100 px. Icons are availble for download in PNG and vector (SVG, PDF, EPS, and more).
The icon consists of what looks like three overlaid triangles. They form one rightward-pointing equilateral triangle. Inside it are inlaid two acute triangles, pointing to the right. One triangle is pointed slightly up, and the other slightly down.