You can switch in web developer mode (web inspector) on the ipad, which will provide access to debug logs in a Safari browser. I think from memory the debug menu is hidden within preference on your laptop and the web inspector logs are located in the advanced menu for Safari (under general settings) on IOS device.
It is unlikely to be the phone is causing the issues, its most likely to be settings on the Web-Server, QlikView Server or blocked ports. What authentication option are you using ?
Which version of QlikView are you using Small Business Edition or Enterprise Edition? Which release of QlikView are you working with?
Has remote mobile access worked correctly in the past ?