A few years ago Google bought the Nik software company. They began to sell the Nik photo editing suite and integrated some of Nik’s technology into google Photos. March 23, Google announced that all the tools in the Nik editing suite are now available for free. The Nik suite includes Analog Efex Pro, Color Efex Pro, Silver Efex Pro, Viveza, HDR Efex Pro, Sharpener Pro, and Dfine.
It used to sell for almost $500US!