Are you using SSL (https) for your mobile access. Is your SSL certificate signed by a trusted authority or are you using the stock certificate shipped with Qlik Sense? If you do not use a signed trusted certificate, then iOS8 will block ALL ACCESS to your server. There is no way around it, it's a iOS security feature.
Enable http on your QMC and then access Qlik sense from your mobile device using pure http, or install a signed root certificate on your http server.
Also, look at the following threads for more advice: