DualShot: A Frontback Clone for Windows Phone
The app is free and it works just as you'd expect saving a photo to your camera roll. The The app offers a small selection of pretty mediocre filters (if that's your thing), the usual sharing options including 6tag support and an option to set the photo as your lock screen. With a quick, simple and well designed interface much like Frontback the app is a must download.
Get it now: DualShot