IPod the iPod Nano and Shuffle from its stores, marking the end of Apple producing standalone music players. Currently, the iPod Touch is the only iPod produced by Apple. The third-generation iPod had a weak bass response, as shown in audio tests. The combination of the undersized DC-blocking capacitors and the typical low impedance of most consumer headphones form a high-pass filter, which attenuates the low-frequency bass output. Similar capacitors were used in the fourth-generation iPods. The problem is reduced when using high-impedance headphones and is completely masked when driving high-impedance (line level) loads, such as an external headphone amplifier. The
IPhone 5S iOS 7 and OS X Yosemite (version 10.10) noticeably departs from skeuomorphic elements such as green felt in Game Center, wood in Newsstand, and leather in Calendar, in favor of flat, colorful design. iOS 7 adds AirDrop, an ad-hoc Wi-Fi sharing platform. Users can share files with the iPhone 5 onwards, the iPod Touch (5th generation), iPad (4th generation) onwards, or iPad Mini (1st generation) onwards. The operating system also adds Control Center, a control panel accessed by swiping up from the bottom of the screen. Control Center contains a number of commonly used functions, such as volume and brightness