David Hockney is a celebrated artist who has had his iPad artwork featured on the cover of the New Yorker several times.    http://www.newyorker.com/online/blogs/newsdesk/2011/06/cover-story-he-draw-on-ipad.html

The video above features many of his iPad paintings on display in his current exhibition in London. 
We have only just begun to explore digital painting on our iPads at B.A., but look forward to having more opportunities.  

See some of our artists first digital paintings here in our Artsonia gallery.http://www.artsonia.com/museum/gallery.asp?exhibit=442699