First the product shows nonsensical results which were reported, but the author didn't react.
Secondly the product definitely uses external content and the author didn't put the proper warning, for example in admincp/slowplugins.php
line 15 : <script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>
I have recently received an email on a mail address I have never use besides receiving notification from my vbulletin, I'm trying to find where is the backdoor and this one product seems to be the most suspicious of all, it has left tons of data in the sql database even after uninstall.
I think the code of this product should definitely be audited.
Jquery isn't malicious code. Virtually every software program uses it. Hell, vBulletin uses it.