For Android:: you can use Android SD kit that available for free of cost. and you can merge the tool kit with Net beans software. So that the applications can be developed in the Net Beans environment itself!! there are lot of built-in interfaces available for java applications to develop the localized application in an easier way.
There are plenty of projects out there that worked on this issue. One of the best documented ones is iDocent from Uni Michigan (http://www.egr.msu.edu/classes/ece480/capstone/spring11/group02/documents/final_report.pdf). I think they even published the code of their App.