GlassCamera (US$0.99) gives you the ability to shoot your photos and movies through a variety of simulated glass lenses. It's sort of like imaging through church windows or distorted glass. The app provides 21 glass lenses, and each has a slider control you can use to change the degree of distortion. There is also a set of embossing filters.
You can view the effects in real time, either in the still or video mode. The app also lets you apply effects to existing photos or movies. While you are in camera mode, you can touch to focus, choose the front or back camera, and turn on the LED flash as needed.
I gave the app a tryout today, and it worked without surprises. I noted that video was not recording at full resolution, but the developer says full 720p HD recording is coming in an update. Stills are also not at full resolution, as my samples came out at 1136 x 640. I think it should be a high priority for the developer to match the output of this app to the capabilities of the camera.
The effects are not the kind you are going to use for every photo or video, but when you want something unique, this app will do nicely. While the glass effects are unique, the embossing effects are available in many other apps, so don't get this app for the 3D embossing effect. I consider it a nice bonus on top of the glass effects, which are quite interesting. With full resolution output this app would be exemplary. As it is, it's very interesting, but can't give you the highest quality output.
GlassCamera requires iOS 4.3 or later. It's a universal app and it is optimized for the iPhone 5. You can see some examples of the filters at the iTunes Store GlassCamera page.