Screen pinning will temporarily lock your display to show the app you've chosen and you won't be able to exit unless you unpin it. 
	 
 This prevents you from accidentally exiting an app if you press a navigation button especially when playing a game in landscape orientation. When you need to lend someone your HTC device, you can also restrict them to just use a single app by pinning it. 
  
Here's how to pin an app: 
	 
- 
Go to Settings. 
			 
 
- 
Tap 
			 Security, and then tap 
			 Advanced. 
		  
 
- 
Tap 
			 Screen pinning, and then tap the 
			 On/Off switch to turn it on. 
		  
 
- 
Choose whether to be prompted for your screen lock PIN, password, or pattern when unpinning. 
		  
- If you haven't set a screen lock yet, tap 
				Lock device when unpinning to set it. 
			 
 
- If you have set a screen lock, tap 
				Ask for PIN/password/unlock pattern before unpinning if its 
				On/Off switch is not turned on. 
			 
 
 
- 
Open the app that you want, and then press the RECENT APPS 
 button. 
		  
 
- 
Tapp the icon at the top of the app to display a menu, and then tap 
			 Pin 
.