Google yesterday launched a free iPhone app for their Photo Sphere Camera tool. Photo Sphere originally launched in October 2012 as an Android 4.2 feature, allowing people to create their own panoramic views that can be uploaded to Google Maps. The new iPhone app is simply a port of that original Android functionality and allows you to take your own 'Photo Spheres' with an iPhone (4S and above). Unfortunately you can't view other people's Photo Spheres in the app - just ones that you have made and two samples.
It reminds me a lot of Microsoft's Photosynth which has had an iPhone app for some time. Photosynth also has the advantage of letting you save a static panorama to your camera roll or even share an interactive Photosynth (where you can make it unlisted). By contrast, if you want to share a Google Photo Sphere, your only option is to publish it to Google Maps. On the plus side, Photo Sphere did seem to make slightly better quality panoramas in my testing.