Google Fonts - Making the web more beautiful, fast, and open through great typography
Responsive Viewer - View multiple screen dimensions in one view
Typewolf - Typewolf helps designers choose the perfect font combination for their next design project—features web fonts in the wild, font recommendations and learning resources.
Responsive View - Test your responsive design across different devices
Font Generator - Tons of font ideas in one click
Auto-Layout for Sketch - Responsive design for Sketch