Spectre Long-Exposure iPhone Camera App Now Free, Ushering in Spectre Pro Spectre, the long-exposure AI-powered iPhone camera app made by the developers of the popular Halide photography app, is now free. For those unfamiliar with Spectre, the app uses a computational shutter to take hundreds of photos over the course of a few seconds to create an up to 3-second long exposure. Because it’s taking hundreds of image…