Sprite Painter - Built-in Image Editor
GDScript
It paints sprites... and not just them. Just press the colorful button above the viewport to edit a Node's texture, or an image file in the project folder! - Classic, customizable tools, including the 1-pixel Pencil, the round Brush and Eraser, Solid and Gradient fill, Box and Wand selection, Shape and Line drawing; - Clone, Fill and Normal Map brushes for more drawing possibilities; - Some Scripts to change the whole image or just the selection; - Quick operations on the image: flip, rotate, and resize; - Hold Alt to pick color from image or editor window; - Grid overlay for Sprites with Frames and Maps with Tiles; - Region overlays for Atlastextures and Spriteframes; - Full Undo support.
Get it → github.com