Heytools - JavaScript tools, AJAX tools and some fully server side tools.
Framer Inventory 3 for Sketch - Import states & export prototypes from Sketch to Framer
WordCounter.net - Count words, sentences, paragraphs etc.
Select Similar Layers - Sketch plugin to select layers with the same attributes
TextBuddy for macOS - A Swiss Army knife for plain text.
Fluid for Sketch - Sketch plugin to make your responsive designs more efficient