Its nothing at all to do with GN, Kate They are pop ups, which I think are connected to apps, you may have downloaded, or sites you have browsed.
I don't know much about iPhone, but would this info help?
How do I stop pop up ads on my iPhone?
On your iPhone, iPad, or iPod touch, go to Settings > Safari and turn on Block Pop-ups and Fraudulent Website Warning. On your Mac, you can find these options in Safari > Preferences. The Websites tab includes options to block some or all pop-up windows, and you can turn on fraudulent site warnings in the Security