Blokk is a font specifically made for mock-ups and demos and is an excellent looking alternative to Lorem Ipsum. It could come in handy in the case of an edge of the art design that wouldn’t usually mix well with latin on it.

A front-end framework for building responsive websites. It makes your websites responsive and look good both on small and on huge screens with a well done grid system and tons of CSS and JS features. There are lots of additional resources and plugins for bootstrap, as well as alternative frameworks like foundation.

Browershots is an online tool that simulates how a webpage looks on different browsers and gives you “screen” shots to inspect.

Freepik offers a colossal collection of vector art, illustrations, SVGs, PSDs and stock photos. Everything is free and categorized neatly so you shouldn’t have any problem finding what you need, although you might have a hard time choosing, since there are over 1,4 Million items to date.

Google Fonts makes it quick and easy for everyone to use web fonts, including professional designers and developers. We believe that everyone should be able to bring quality typography to their web pages and applications. Our goal is to create a directory of web fonts for the world to use. Our API service makes it easy to add Google Fonts to a website in seconds. The service runs on Google's servers which are fast, reliable and tested. Google provides this service free of charge.

A fun to use color picker. It handles choosing the hue, lightness and saturation of colors in a unique and cool way.

An awesome online service with a brilliant idea behind it. Color Thief lets you upload an image and get the color palette for it, as well as its dominating color. Very helpful for making design decisions.

This app makes creating stripe patterns easy as child’s play. Patterns can be saved and shared with anyone, allowing for collaboration and remixing.

Responsinator helps website makers quickly get an indication of how their responsive site will look on the most popular devices.

An amazing resource for high quality textured patterns. A lot of great artists have contributed there to create a collection of really sharp and versatile images. Oh, and browsing on their site is quite enjoyable as well.

This one is called picresize(.com) but what it can do goes beyond what its name suggests. This neat tool lets you apply filters, crop and convert the file format of your image.

Pixlr is an amazing image editor with rich functionality. It works similarly to the way offline image editing software do, with the difference that this launches straight in the browser. Although it has been around for a number of years, it is still one of the best free online image editors out there.

Placehold.it helps you create dummy images for usage as placeholders in designs. After you select the size of your pic you can simply copy the provided link and put it in the img tag.

Placeit.net is a tool for creating awesome mock ups for your website or demo by placing them on the screens of computers and devices in stock images. It includes hundreds of cool designs to choose from and is rather easy to use.

This one is still in beta but still is a great tool for creating favicons. Instead of giving you just one basic icon, realfavicongenerator.net lets you create specific icons for every OS.