DISCLAIMER
This app isn't very secure. I created it to brush up on the use of SharedPreferences in Android, and put it on GitHub in hopes that it may help someone else to do the same. The app was quickly put together soley for practice. It does not have any encryption whatsoever.
In reality, a rooted device can easily gain access to SharedPreferences. If you really wanted, you could obfuscate the text in the SharedPreferences to act as some sort of security, but I haven't done so. Also it is not reccommended to use setContentView multiple times, but rather a ViewFlipper.