Paint Editor Extension

Paint Editor is a free rasterized graphics editor that works directly inside Unity. It lets you load and edit images of your own, or create completely new ones for your games. The editor lets you paint and erase, fill sections, select and transform sections of the canvas, use multiple layers to compose an complex image, and add blending modes to those layers. Some other functionalities are provided such as Undoing and Redoing actions, Navigation for moving the canvas inside the window, and Zooming in/out. Check the Paint Editor's GitHub repository for more information.