When you install an app, the system often adds an app icon on your home screen. This icon works as a shortcut to run the app. In case you need to manually add an app icon or a widget icon yourself, it's pretty easy
Tap the All Apps icon 
on the tray.
Select the Apps or Widgets tab on the top.
Tap the All Apps icon on the tray.Select the Apps or Widgets tab on the top.
Touch and hold the icon you want to create a shortcut.
Drag and drop the icon on a home screen you like.
To remove an icon from your home screen:
Touch and hold the icon of apps, widgets or shortcuts until the Remove icon appears on the top.
Drag and drop the icon over the Remove icon.
Note: On Android 2.x, you can add a shortcut icon by touching and holding an empty location of a home screen or press Menu then tap 'Add'; On Android 3.0, touch the customize button
at the top right of a home screen to add a shortcut icon.
Drag and drop the icon on a home screen you like.
To remove an icon from your home screen:
Touch and hold the icon of apps, widgets or shortcuts until the Remove icon appears on the top.
Drag and drop the icon over the Remove icon.
Note: On Android 2.x, you can add a shortcut icon by touching and holding an empty location of a home screen or press Menu then tap 'Add'; On Android 3.0, touch the customize button
at the top right of a home screen to add a shortcut icon.