
Android Application Development Cookbook
By :

Android provides many ways to notify your user—from non-visual methods, including sounds, lights, and vibration, to visual methods including Toasts, Dialogs, and Status Bar notifications.
Keep in mind, notifications distract your user, so it's a good idea to be very judicious when using any notification. Users like to be in control of their device (it is theirs, after all) so give them the option to enable and disable notifications as they desire. Otherwise, your user might get annoyed and uninstall your app altogether.
We'll start by reviewing the following non-UI based notification options:
Then we'll move on to visual notifications, including:
AlertDialog
ProgressDialog
The recipes that follow will show you how to implement these features in your own applications. It's worth reading the following link to understand "best practices" when using notifications:
Refer to Android...
Change the font size
Change margin width
Change background colour