Synfig Studio - Just another WordPress site
Free Texture Packer - Free Texture Packer is an open source tool that allows you to pack multiple images into one atlas for you games or sites.
Creature - Creature 2D Skeletal and Mesh Animation Tool
Sprite Monkey - Small and fast but still full-featured sprite sheet editor.
Live2D Cubism - Live2D is the world's first drawing technology to enable 3D rendering of 2D images.
ShoeBox - Free unlimited photo storage, so you can rediscover your photos anywhere. Available for iPhone, iPad, Android, Mac and PC.