you probably wont be able to find a good app for that, at least i wasn't able to. i just use photoshop to correct the white balance and color. its a lot cheaper than a fancy camera, especially when you don't pay for it
I second this. Another option if you think Johnny Law is gonna knock down yer door is to just buy the monthly pass. I think it's like $20/month, so you could just pile up the pics and then buy for a month, edit them all, then wait again so you don't have to pay $20 every month, just the when you need it.