This is an example project for android REST API calls. The JSONParser Class supports GET and POST HTTP-methods and loads a JSONObject in background.
Within test_activity it is shown how to get access to the JSONObject (just transfer the method you want in transfer[1])
Check out https://github.com/larissa95/PythonServer for a python test server. Check out https://github.com/quappi/FRServer for REST API calls in Objective-C.