how I can't avoid both the app close and the go in background?
<p>I want to use android for a single application only. </p>

<p>Means this application will always running and visible for user interaction, it shouldn't close or go in background and also should not allow user to access other application without permission from this application.</p>

<p>(it is for a business app, no for a market app, I don't want to annoy any user, is just a bussiness rule)</p>

<p>how I can do this?</p>
