My HTC One has suddenly started showing an Axa health ad each time the phone is switched on. Given I have some 70 apps on the phone, is there a way to identify which app is triggering this ad to display when the phone is switched on. Failing that, is there a way to stop the ad showing (I'd prefer not to have to add yet another app - i.e. an ad-blocker - I'd rather solve this problem at source). Thanks.