I have been using CodePen a lot for sketching out a web version of a designer’s idea. This is actually something I have been working on recently for my current contract role. I was later able to copy and paste this code to the relevant files in the actual app and it “just worked”, so was very pleased with that.
The QR code shown is pulled from an external source on-line but it could just as easily be pulled in from your own database.
In this very dynamic industry you have to keep up with techniques – So I am focussing on SASS at the moment.