IPod that put "1,000 songs in your pocket." Apple did not develop the iPod software entirely in-house, instead using PortalPlayer's reference platform based on two ARM cores. The platform had rudimentary software running on a commercial microkernel embedded operating system. PortalPlayer had previously been working on an IBM-branded MP3 player with Bluetooth headphones. Apple contracted another company, Pixo, to help design and implement the user interface under the direct supervision of Steve Jobs. As development progressed, Apple continued to refine the software's look and feel. Starting with the iPod Mini, the Chicago font was replaced with Espy Sans. Later iPods switched
IPhone 5C polycarbonate housing, which is strengthened by a steel band. However, due to the material of design changes, the phone weighs 132 grams, which is 20 grams heavier than both the 5 and the 5S, but still lighter than older iPhone models. The design of the iPhone 5C is also considerably thicker but closely similar to the design of the iPod Touch (5th generation) models, which is also available in a variety of colors, but in a different coating finish. Other minor changes include a different camera assembly and the design of the mute/ringer switch. This iPhone received positive reviews for