I've just released a BETA (I can't stress that enough) of a responsive version of Decaf, for Moodle 2.6 and above. You can grab it from the plugins database.
Although the major Decaf functionality is in place (including a couple of new features that had been requested), there are a couple of things to note:
- The Awesomebar is not yet responsive. I have plans for this, but haven't got it done yet.
If you've been waiting for a responsive version of Decaf, please try it out (NOT on your live site!) and post any feedback here. Any and all feedback is appreciated - things you like, problems you've encountered, missing features, new feature requests, or anything else.