The free app is designed specifically for the iPhone. However, I installed and tested it on my iPad 2. The screenshots here are from the iPad 2.
Multiple photos can be recorded and previewed on the iPhone as you create your panoramic scene. You can take photos in any direction and do not have to sequence them in any specific order. Stitching the low resolution sub-megapixel iPad 2 images took just a few seconds.
After the multiple photos are blended into a single explorerable scene, you can share it on Facebook, Bing Maps, or directly to the PhotoSynth website. The photo will be automatically stored on PhotoSynth no matter which sharing option you choose. So, you may want to consider your PhotoSynth site account name carefully depending on how much or little anonymity you want.
I was very impressed by the photo taking process, panorama creation process, and the explorable view on PhotoSynth’s website.