The DFU mode, namely the device firmware update mode will be woken up when you upgrade the iOS on your iPhone, iPad or iPod. When your iOS device is in this mode, the screen of your iOS device will be black and you can not disrupt this process by simply touching the screen. Then if you want to stop the DFU mode, there are some ways out.
On the iPhone, it is really easy to delete the apps, simply to tap on the icons for a few minutes and then click on the “x” icon of the app that you what to delete. Thus, you may also delete the apps on your iPhone 6S Plus / 6S /5S/5C/5 by accident. In this time, there are ways to help you undelete the apps on iPhone with ease. Now you can see two methods in the following passages: