Upside Down allows you to turn any webpage upside down in google chrome, this way you can play a prank on your friends computer by turning any page upside down in google chrome.
How to Use this extension to flip pages upside down
This extension does not add any button in the google chrome toolbar, rather you will need to go to Extensions and then click options button on on this google chrome extension and then configure the time in seconds after which whole pages or images should turn upside down.
Please note that existing tabs already opened in google chrome will not turn upside down but the new tabs after enabling this extension will turn upside down.
Install Upside Down Google Chrome Extension