[eugenijusr]

First of all it depends on the app. If it's a public service I personally find that having this constraint of making your app work with JavaScript off leads to a better web architecture. It doesn't break the web and pays off in the long run for whoever might integrate with your app or whatever products might consume it now or in the near future. Graceful degradation is not all about the end-users.

So my advice would be if you're building a JavaScript only app you have to really know what you're doing, because it's very easy to get carried away with it. Keep in mind that you risk making it "incompatible" with the web. When a need arises to be "compatible" you might end up finding yourself building second version of the same app.