I don't have a cool cell phone to use apps to filter my pictures. I think that the pictures taken with apps can look really cool though. I think someone should make an app that does what I did in Photoshop to the following photos. My wife calls it blueprint style.
Transamerica Building in San Francisco
Nob Hill Hotels in San Francisco
Sear's Tower (Willis Tower) in Chicago
Lone Cyprus in Monterrey California (I'll call it antique blue China style for more organic shots)
Another shot on the 17 mile drive in Monterrey. Note: Brown can work as well I think.
I don't see why a camera app couldn't do this. All I've done is remapped where the colors go. You could have a couple of sliders down at the bottom and adjust until the shot looked good.