Photosynth is an iPhone photo stitching iOS program developed and introduced to the Apple Apps Store in 2011 by Microsoft. This highly rated (4+ stars) app is free. Most iPhone panorama apps can only stitch horizontally, but Photosynth can stitch horizontally and vertically creating a sphere-like and slightly fish-eyed image perspective after the image-stitching engine is done.
All panorama apps have the photographer capture a series of aligned frames to stitch together to create the final panorama. Photosynth does not require the photographer to visually align each successive frame of the developing panorama like some apps similar to Pano. Also, the user doesn’t have to manually engage the camera’s shutter when the frames may (or may not) be properly overlapped. Photosynth just asks the photographer to slowly move the iPhone around until the app is happy with the next potential frame alignment (indicated with a green rectangular frame), upon which, Photosynth records the frame on its own approval. If the next frame is not aligning properly (indicated with a red rectangular frame) no frame is captured and Photosynth waits for the photographer to move and hopefully improve the camera’s holding position. The shooting process is difficult to explain, but the app interface is very intuitive and simple to understand after only a few panoramas. Hats-off to the app devs who created this unique user interface, the UI (User Interface) is so elegant and simple, that iPhone photographers can quickly understand this panorama shooting process.
The Photosynth app has image sharing features and photo geo-tagging integration with Bing Maps. The only negative that I have encountered is the low image resolution compared to what the 8 megapixel iPhone 4s camera can capture.
Photosynth has two viewing modes; plain image and interactive panorama. To view images interactively, you must have a web browser that is running in 32-bit mode and has Microsoft’s Sliverlight plugin, then, you can control the magnification and view direction of the panorama.