I recently found this repository and so I added the compile statement to my build.gradle and it creates these warnings on debug:

WARNING: Dependency org.json:json:20090211 is ignored for debug as it may be conflicting with the internal version provided by Android.
In case of problem, please repackage with jarjar to change the class packages
WARNING: Dependency org.json:json:20090211 is ignored for release as it may be conflicting with the internal version provided by Android.
In case of problem, please repackage with jarjar to change the class packages

I'm running android 4.4.4 on my device.