General Assembly launches Dash, a Codecademy-style site that teaches you to code (thenextweb.com)

I'm not sure about Dash (haven't tried it yet), but General Assembly puts out incredibly high quality courses taught by people working at well-known companies. If you live in NY or SF, take a look at their course listings: https://generalassemb.ly/

In the context of code, "Dash" makes me think of the documentation browser: http://kapeli.com/dash

I hope that's not confusing enough to cause problems for either of them.

What new features does Dash offer? The only one OP mentions is viewing your code on a simulated mobile device. While that's useful, it's not particularly relevant to the target audience of beginning web developers.

Note: Learned the basics of web programming from Codecademy - extremely helpful service.

I think the pace of the course is too fast for the beginner. For beginners, trying Codecademy or Treehouse might be better.

Do you know if they get to advanced concepts about front end design? :)