launching android widget

I am following http://www.helloandroid.com/files/xmaswidget/android_howto-hellowidget.pdf for developing a widget. I am unable to launch a widget on to the home screen. When running the application I am getting the errors like No Launcher activity found and The launch will on开发者_Go百科ly sync the application package on the device! Looking for an answer.

It could be that you don't have the right setup in your AndroidManifest.xml

Have you seen this post? Android sample app not showing up