There is a large digital display that needs to display pictures from various places, like twitter, flickr, smugmug, http dir listing, dropbox, local NAS, etc.

I have an Android stick device to run the display, but need an app to do it right.

Once images are available and aggregated they need to be fully displayed, zoomed correctly to completely fill the screen with no border lines on top/bottom or sides. Basically, "Do The Right Thing(tm)", no matter if the image is portrait or landscape.

Ken Burns effect would be nice too, where the image zooms in/out and pans slowly for added effect.

Ideas?