Preventing Android app from closing
<ol>
<li>Is it possible to prevent an Android app. from closing?</li>
<li>Is it possible to do this without modifying the OS?</li>
</ol>

<p>I don't want the app. to close unless the user authenticates with a password or some other mechanism. I don't want any system settings changed without authentication either.</p>

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<p>I want to use an Android tablet in stores and offices. I don't want customers messing with the OS or breaking stuff. So, I want the tablet locked to one app. until an administrator authenticates.</p>

<p>I don't want any modifications to the tablet, but I do want one app. to be functional.</p>
