Do you receive any console errors when running on a device?
When an app works in the browser but not on a device it's often caused by not including the whitelist plugin, or not having it configured correctly with the Content Security Policy tag in your index.html file, e.g:
<meta http-equiv="Content-Security-Policy" content="font-src 'self' data:; img-src * data:; default-src * 'unsafe-eval' 'unsafe-inline'">
(this is a very permissive CSP, you might want to use something more restrictive)
That may or may not be the issue, I just had a quick look and noticed it wasn't included in your index.html file (you also need to add the whitelist plugin if you haven't already, not just this tag) - your best bet will be to just use something like GapDebug and check the console errors when running on a device.