Understanding Title bar in Android - When useful when not

I did not find any explanation hence putting this together

Title Bar refers to the top band which shows the app name.
For home launchers it is not required. So always select a theme which has NoTitleBar in it.

Example

android:theme="@android:style/Theme.Wallpaper.NoTitleBar"

This will give you a clean page with wallpaper.

For normal apps : Title Bar is useful as it informs the user which app he is using.

Theme.Wallpaper.NoTitleBar,FullScreen : This will give you a page which does not have the top bar.