Are you saying the pen doesn’t work or adding the code from the pen doesn’t work?
If you are talking about the pen make sure you toggle the toggles. They add the hide-footer class to the body and the my-footer class to the footer. I made them toggles to show the effect.
If you are saying it doesn’t work when run on the actual android device it could be related to the android:windowSoftInputMode setting on your activity in the AndroidManifiest.xml. It should probably be set to “adjustResize” to do what you want.
Beyond that we are going to need a lot more info than “it doesn’t work”