Lozad.js - Highly performant lazy loader in pure JS
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.
Dragula - A drag and drop library for developers
Sprite Monkey - Small and fast but still full-featured sprite sheet editor.
JSconsole - Load external JS libraries in your favorite console
ShoeBox - Free unlimited photo storage, so you can rediscover your photos anywhere. Available for iPhone, iPad, Android, Mac and PC.