Odesk and the others aren't a good indicator of the average hourly rate for this sort of work.
Someone charging a freelance rate of $30/hour in north america for iOS work is either not invested much in learning the platform in-depth and therefore won't be able to do much more than populate table views and wire up transitions, or they'll tackle a complicated project at that rate and make a mess for someone else to clean up.
Someone charging a freelance rate of $30/hour in north america for iOS work is either not invested much in learning the platform in-depth and therefore won't be able to do much more than populate table views and wire up transitions, or they'll tackle a complicated project at that rate and make a mess for someone else to clean up.