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 be accessed by a hardware button below the screen on all models expect for the iPhone X where the user must swipe up. The original iPhone contained the following apps: Messages (SMS and MMS messaging), Calendar, Photos, Camera, YouTube, Stocks, Maps (Google Maps), Weather, Voice Memos, Notes, Clock, Calculator, Settings and iTunes (store). The App Store was introduced for the iPhone 3GS and iPhone 4. Compass, FaceTime and GameCenter were added in iOS 4 and 4.1 respectively. In iOS 5, Reminders and Newsstand were added, and the iPod application was split into separate Music and Videos applications. iOS 6 added