Once you've got a picture to work on, you can choose the filter from either the drop down list (tap and select from the options) or slide the pictures left and right with your finger to choose a filter, which is previewed on screen for you.
What to do with the image now you've altered it? Well, CameraBag lets you email it from inside the application (handy if you've set up Facebook to accept posts from an email client), or save it back to your smartphone so you can use any built in application to share the photo.
Simple. Intuitive. Minimal interface.
Suitable for your phone