You most likely have a malicious app that you installed on your phone.
So several people have trouble with one particular site on their phones and you'd say it's an app? I think the common denominator, that we all have trouble with one particular site, is more likely the cause. It'd be hard to believe everyone on this thread has some sort of app that is the same among all of us.
I saw a thread posted a few weeks ago about the same subject but that one seems to have disappeared. It's good to see that there is some real conversation on this this time.