We are currently working on a application with similar features called Leonardo although Leonardo is streamlined for digital painting, not photo editing.
Leonardo is still at least 6 months away from being released but all the features like "unlimited canvas", "instant painting" and handling of "huge files" are already in place.
Unfortunately there is no video right now showing the "unlimited canvas" and "instant painting", but I can make one within the next couple of hours... :)
Leonardo is still at least 6 months away from being released but all the features like "unlimited canvas", "instant painting" and handling of "huge files" are already in place.
Main website: http://www.getleonardo.com (not much there yet)
We also just started a Vimeo channel were we "blog" about the progress of Leonardo: https://vimeo.com/channels/sol/
Unfortunately there is no video right now showing the "unlimited canvas" and "instant painting", but I can make one within the next couple of hours... :)