JSDares is a website which offers learning important JavaScript concepts through creating games.

JSDares was created by Jan Paul Posma and – interestingly enough – by the University of Oxford.

JSDares has a number of cool dares to try and this might make for a very fun way of brushing up your JavaScript or starting to learn it.

Dunked is a website in which you create your own online portfolio without any code.

The portfolios created with Dunked are retina-ready and fully responsive. The portfolios are easy to edit while remaining thoroughly customizable. It is used by more than 20k people from all around the globe. Best of all, it’s completely free!

CSP Header Generator is a web app for generating a content security policy header. 

That… probably doesn’t explain a lot. However, the key thing here is that Content Security Policy mitigates security threats by defining where a website can load its content from. It can protect your website from vulnerabilities such as XSS if the website has user-uploaded content.

The HTML5 spec is at its baby steps at the moment, so different browsers use CSP differently. The generator will ensure that all browsers follow the same rules for uploaded content.

Web Colour Data is a web application for extracting color profiles from websites.

Web Colour Data actually delivers not only color palettes, but intelligently breaks down the colors used in the website requested.

The web app illustrates the hues with a nice distribution graph and even shows a color wheel that pinpoints the colors. Indispensable for designers.

Litmus Scope is a free bookmarklet for creating web versions of emails for sharing.

Litmus Scope works for most web mail clients, such as Gmail. Litmus Scope is useful if you want to share an email design; it also has a code inspector for quickly seeing the magic behind the curtains.

It’s also useful for non-designers: you might want to share an email with many people without actually emailing them. Litmus Scope can also obscure your personal information in an instant, thereby making this app even more useful.

Screenqueri.es is a responsive design testing tool that tests your design on more than 30 different devices.

Screenqueri.es is very precise and can serve as a starting point for your mobile designs. It can test how your design will look on the iPhone, iPad, Android phones and many others.