I'm currently using two methods to attempt text outlining on my Board Horde game, which both seem to be viewable on my ipad (over the web. Not sure what the results would be when using CocoonJs or something).
I created a retro style font to use in the game; rather than importing it as a font, I created each letter on a vector package (inkpad) arranged the letters within the package to spell out the words I needed, and imported the words as different frames of the one sprite. This is a very time consuming way of doing things, as every time I need a new word I can't just type it in and have to copy and paste each letter, arrange them, and then import them.
So the second method which I've recently used (currently only to display the players name in the game, after its been typed into the text box) is to create two Webfonts using the trial version of Font Creator (which is a months limited trial, and limits the fonts you can export though you do get all the letters and numbers that you need); one of the fonts is slightly thicker than the other and acts as the outline for the thinner font when overlaid as two separate Text objects in c2. The advantage of doing things this way is I can now type whatever I want rather than having to arrange each letter by hand, which is a lot more flexible. I still have a few problems to iron out, as occasionally the outline font will appear on the screen a fraction of a second before the text overlay which looks a bit odd. Also it can sometimes take a while for the webfont to register.
Anyway, I'm sure there's got to be an easier method for displaying outlined fonts on iOS devices! But, if not, my gung-ho methods might work for you (both types of outline text styles can be viewed in my game link above) I will continue experimenting, and let you know if I find a better way or encounter more problems.