Do I use the Ruby or iOS SDK for mobile development with RubyMotion?
Using PubNub with RubyMotion you could use either the native iOS PubNub SDK or the Ruby GEM SDK. We recommend the iOS SDK because it supports extra mobile capabilities. The PubNub Ruby Gem would also work. Do you use CocoPods? Here is an easy install for Cocoa Pods
gem install cocoapods gem update cocoapods
Then follow the steps provided in this doc about Configure a CocoaPods Podfile.
Thanks for dropping the knowledge!