Channels are automatically updated by Roku. Public channels are generally updated on the boxes within approximately 24 hours
after approval by Roku, private channels don't require approval, and are updated within approximately 24 hours of publishing. Users can also force pending updates to arrive quicker by visiting the channel store and exiting it using the up button. There's nothing your app needs to do to make this happen, it's a built-in feature of the channel publishing system.
Remoku.tv - A free web app for Roku Remote Control!
Want to control your Roku from nearly any phone, computer or tablet? Get started at http://help.remoku.tv
by Apps4TV - Applications for television and beyond: http://www.apps4tv.com