2nd update, March 2014: Apple closed the bug saying they don't have enough information, but my project is a big PHP application that I can't (and won't) fully send to Apple for them to reproduce this problem. If anyone has a shareable, simple, pure HTML app that exhibits this problem as well, please let me know and I'll submit it to re-open the bug hoping they'll look into it.
1st update: as more users are reporting this issue and nobody has a clue, I have filed a bug report at Apple. If anything useful comes out of that which is not under NDA, I will post it here.
After installing a (jQuery Mobile) web app I am developing to the home screen of my iOS 6 device (iPhone 5), the network activity indicator in the status bar at the top of the screen keeps spinning even after the page is loaded completely. The behavior shows only when the page is opened through the web app; surfing to the same page in Safari on the same device doesn't show the infinitely spinning activity indicator.
Removing all AJAX calls and page content doesn't make a difference; the problem persists even when the web app consists only of an empty page like this:
<html>
<head></head>
<body><br/></body>
</html>