tadaa 3D doesn't create real 3D images, but it can bring some depth to your photos and the result will likely delight friends and family.
The US$3.99 app is disarmingly simple to use. (The app is listed as free as of August 30. That may change.) You can snap a photo from within the app, or create a depth image from your photo library. You select a picture and then use your finger to mask out a foreground object or a person or persons in the photo. The image can be enlarged for more masking accuracy, and the app does provide some intelligent processing to try and figure out what you are trying to mask out using edge detection. When you are finished, you'll see a pseudo-3D image. The background blurs, and as you move your iPhone up and done or side to side, the foreground image moves in relation to the background. It's a nice effect -- not real 3D, but still pleasing to the eye.
The image is shared via the usual social services, or sent via email or text message. A person viewing the image on an iPhone with motion sensors will get the full depth effect. If you send a photo to a user on another kind of phone or a computer, they will see an animated image similar to an animated GIF where the image toggles back and forth to give a depth effect. When viewing on a computer, you can also use a mouse to change the faux perspective.
I tried tadaa on a few photos with foreground objects and some with people in the image. The app works as expected, and masking the foreground objects is pretty easy. To make it all work you need a free account with tadaa since the images are hosted on the developer's servers. Images you take are private, only viewable by yourself and those you share them with, unless you decide to be part of the tadaa social community. In that regard, tadaa 3D is similar to the social photography community created by Instagram.
tadaa 3D is a well-crafted app that performs a unique function. The app requires iOS 6 or greater and is optimized for the iPhone 5.