So I have had the popular ones like Camera+ and ProCamera, both of which are extremely nice. Today, I bought Mattebox. It's universal so it works on the iPad too. You can save in JPEG or TIFF, which is nice. Plus, this is the selling point, you have access to countless filters made by the Mattebox community, all free without an in-app purchase.
I would probably recommend this camera app, just based on the filters.
I would probably recommend this camera app, just based on the filters.