IPhone not user-replaceable. The iPhone can be charged when connected to a computer for syncing across the included USB to dock connector cable, similar to charging an iPod. Alternatively, a USB to AC adapter (or "wall charger", also included) can be connected to the cable to charge directly from an AC outlet. Some models of the iPhone support wireless charging. Apple runs tests on preproduction units to determine battery life. Apple's website says that the battery life "is designed to retain up to 80% of its original capacity after 400 full charge and discharge cycles", which is comparable to iPod batteries.
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