The range of creative and practical apps that use the camera in unusual ways is astonishing. Who would have thought that you could use it as a heart rate monitor or a business card reader? There's even an app for those who are colorblind, to show them the colors present in any object you photograph.
Apple made a brilliant decision when it let developers create apps that access the camera input and use it in non-traditional ways. In this month's column, I offer a roundup of some of these apps.