iPhone Duo review: App issues, hinge, and camera flaws

Apple's iPhone Duo faces reported issues including subpar third-party app optimization, a low-quality inner FaceTime camera, and potential hinge wear, though the author's week-long testing found no deal-breaking problems. The FaceTime camera's 4-megapixel sensor produces plasticky selfies, but users can take better photos using the main cameras or outer display's 12-megapixel shooter. Many apps like Gmail appear unoptimized or blurry on the inner display, though Apple's ecosystem suggests rapid fixes. The hinge remains smooth after 10,000 folds in stress tests, with the crease barely visible in real use despite dramatic photos online. Software bugs exist but are typical for new launches, and the device's backorder indicates strong demand likely driving developer support.