The documentation is very thorough, even though it's still in development stage (as usual). I'm currently implementing an open source project that uses Zeppelins' library to allow users from different countries with their own currencies/currencies rates when paying eachothers transactions fees through our platform; which has been made possible thanks zepplin! Not much yet but i think this will help us scale up as we grow more than expected since there are no limits or restrictions at all regarding who can use them so far - just go ahead :).