https://superhivemarket.com/products/get-sheet-done

• Spritesheet generator for Blender.
• Generate grid-based spritesheets right inside Blender from images or when rendering an animation. Spritesheets are mostly used in popular game engines as animation sheets.
• You don't need any external software - just Blender and this addon - which means it's perfectly integrated with Blender and will run on any platform, with any render engine or image file Blender can use.
• So if you need to combine sprites into a spritesheet or just merge couple images and would like to do that quickly and easily inside Blender - this addon is for you.