LoryStripes is a new photo app that allows you to spice up otherwise drab pictures with bright ribbons of color. The iPhone and iPad app is $1.99, which I know is probably $1.99 above your price range, but hear me out.
The app has 40 different ribbon styles in 62 colors so you can perfectly select stripes of colors that fit whatever photo you want to spruce up. Plus, if you hurry and download it soon, your friends (who don't read The Bold Italic) will have no idea how you're pulling off your amazing Instagram wizardry.
Basically, this is a beautiful app that you'd actually use. If you're still not convinced, check out the LoryStripes Instagram for more examples and photo inspiration.