The Apple iPhone smartphone can run a wide variety of applications ranging from games and music software to productivity and map software. Sometimes an application might attempt to download an update when the battery is low or you are in the middle of a task. You might also be trying to download a new application but the download is taking too long or has frozen. Stop the download at any time--even if the application is frozen.
Exit out of the program that is currently downloading a file or update. Press the single "Home" button on the bottom front of the phone. This will pause any update or download for that application.
Click on the "Settings" icon on the Home Screen. Scroll down to "Airplane Mode" and click the small toggle icon next to this option.
Tap on the toggle switch icon until it reads "Airplane Mode On." Airplane Mode immediately stops any cellular or Internet data transmissions--both ingoing and outgoing. The download will be stopped.
Hold down the "Sleep/Wake" button on the top right of the iPhone's casing. A virtual slider bar appears on screen. Use your finger to slide the slider bar arrow from the left side to the right side, which shuts the phone down.