React native: Always running component
<p>I don't know actually, how to name this question!</p>

<p>I've a JS file in react native that fetches data from server and compares it to local database. i need this to run simultaneously, how can i achieve that? when app starts, that should run, changing views (navigation to other components) should not destroy it, it should still be running.</p>

<p>Any solutions?</p>