The pictures displayed whilst charging is part of Daydream, go to...
Settings> Display> Daydream.
Here you can change the Daydream mode and if you've activate it you can set Bean Flinger as a Daydream mode. To activate...
Settings> About tablet> Tap "Android version" until the Jelly Bean appears and the long press the Jelly Bean until you get Bean Flinger. Now it will be available in Daydream.
Some 3rd party apps include Daydream modes including Flipboard, Battery Widget Reborn and soon Dashclock will include Daydream mode.
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