A list of the extensions that will help you work much faster.
PNG Hat - Plugin automatically uploads assets to the server and with defined HTML/CSS templates you can paste the picture directly into your code.
CSS Hat 2 - Select any Photoshop Layer and get CSS instantly.
Cut&Slice Me - Use Cut&Slice me to export your assets to different devices in seconds. Improve your workflow by just naming your layers.
CSS3Ps - Free cloud based photoshop plugin that converts your layers to CSS3.
Layrs Control 2 - Free Photoshop extension. A collection of 7 scripts that make tedious job easier.
LiveShare - InVision extension – LiveShare lets you transform your designs into beautiful, interactive web & mobile ( iOS, Android) mockups and prototypes.
Devine Elemente - Allows you to convert a layered PSD file into a full WordPress website including HTML, CSS and PHP files.
GuideGuide - Creates guides and grids based on your document or the selection.
Renamy - Multiple layers renaming Photoshop plugin. You can select a lot of layers and rename it in 1 click. Find and Replace. Use simple text find and replace for layer names.
Web Zap - Create website mock-ups in Photoshop super fast with this great plugin. Web Zap allows you to drag and drop website elements from and library of thousands of styles and components.
Flaticon - Use the FlatIcon plugin to quickly find the icons you need for your design, without leaving your working environment. 63,914 icons available.
Social Kit - Cover images, profile pictures and ad banners in a free up-to-date Photoshop plugin.
PixelDropr - PixelDropr lets you save your elements and other objects of a project to be used at any time in other projects.
Extensis - Google Web Fonts right from within Photoshop.
Bounce - Intergrate Dribbble into your design apps.
Ink - A photoshop documentor plugin.
SpecKing - SpecKing is a Photoshop plugin that provides tools to generate design specs and annotations in a fast and easy way - saving you hours of work!
Oven - Oven it’s a Photoshop plugin that helps you generate layers ready to be exported for iOS and Android.
Size Marks - Size Marks is a helpful Photoshop script for web designers and front-end engineers. Script converts rectangular marquee to labeled measurement mark. Landscape marquee → horizontal mark. Portrait or square marquee → vertical mark.
Subtle Patterns - Imagine the immense library from Subtle Patterns, fed directly into your Photoshop panel – always in sync!
Velositey - Prototype the design of your website in seconds in Photoshop.
Font Awesome - Font Awesome icons right inside Adobe Photoshop.
Duplllicator - Clone layer or group and shift it horizontally or vertically with this extension.
Zeick - Photoshop CC and CC 2014 plugin allows you export vector shape layers to SVG files.
Hexy - Hexy allows you to use the Eyedropper tool to simply click on the color of the object you're after and copies it directly to your clipboard.
Each extension has its own licence, see its homepage.