I am new to android development. I want to make one background application, so that it keeps running in background, and it's without any UI, and even its icon do not appear on desktop.
In short it's a stealth application.
Is it possible?
This is certainly possible. To create an app that does not have an icon in the launch pad, just remove the Activity with the android.intent.category.LAUNCHER category from the AndroidManifest.xml.
To implement your background application it strongly depends on what you want to do. You can create a Service for long running tasks, BroadcastReceivers to react to specific events or Activities with intent filters.
Be aware, however, that your application will be visible in both the file system and in the settings under 'Manage Applications'.
Yeah it's possible look up Service
Read more about the service in tutorials
来源：https://stackoverflow.com/questions/3370659/background-application-without-ui