waterlogue is a nice little photo app. You can transform your photos into luminous watercolors. There are 12 styles to play with. You need IOS7 on your iPhone, iPad, or iPod touch. This app is optimized for iPhone 5. And it is $2.99 in the Apple Store.
I like apps like this when I have a lackluster photo. This allows me to add some interest when I don't have much to work with. Have fun.