Design for Humans - An email course about emotional design
TexturePacker - Texture Packer is hands down the best sprite sheet generation tool on the market.
Simple Grid - Responsive & lightweight CSS grid for your website.
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.
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Sprite Sheet Packer - Sprite Sheet Packer is online that you can easily use to pack sprite sheets, including data formats for CSS, LESS, and Phaser.