title: how to check if plugin or library would bring no harm (PHP,Javascript, Android)
body: <p>I and my partners developing a system (cms &amp; web service) and app in android.<br>
  but I notice as I code deeper more libraries and plugin I used and all of it is opensource that I got from other developer on the internet</p>
  
  <p>like on web I'm using plugin for :<br>
  <strong>*jquery chart</strong><br>
  <strong>*php to excel</strong><br>
  <br>
  and in app in android I downloaded a library for
  <br>
  <strong>*qr code</strong> and <strong>bar code scanner</strong> also <strong>qr code and barcode maker</strong> 
  <br><br>
  but I kept on thinking is this all plugin and library safe or not getting your server or personal info or something
  <br>
  what code should I look for that may bring harm on my end. </p>
  
  <p>I'm a newbie and I'm having a tough and very short time for this system so i depend on opensource libraries.</p>
  
  <p>could anyone give idea please. thanks in advance</p>