Detect mobile devices even when the user switched in the browser

[SaschaAusUlm]

Hey,

I was wondering if there is a good way to still detect a mobile device, even if the user switched the view/site to desktop view in his browser's settings.

We have the problem that the users on mobile devices (well ... phones) might switch that, get the full application on a tiny device, and then complain that they don't see appropriately.

Thanks in advance