Some newspapers have a pop up wanting you to subscribe before you can read the webpage. Often, you can stop it to read the page by just clicking the "X" refresh button on your browser before the page script fully loads. You will probably have to refresh the page several times before you succeed. For example, this webpage:
If you are talking about Android mobile phones, there are third party apps that associate pop-up ads with with the apps you installed. You can then stop the pop-up by deleting the app or in some cases, stop the notification of the app.
Well, I have to think about this one. If you turn on Airplane mode, you have no pop-ups but you are cut off from phone service ( call and tax) , and internet. I suppose you can work on the "local" apps like calculator and take pictures. I would consider the phone is not functional as a communication device. Or you can have wifi on when the airplane mode is on. But then the pop-ups will come.
Quite true, your response but I wasn't suggesting that a phone be permanently set to airplane mode. And I also was thinking only of pop ups in games. I don't get may popups on my phone because I only use it mostly as a phone. Games however will often show ads for other games between stages on phone apps. That's what I was thinking of. I have a tablet and/or a laptop for web browsing and that's where popup ads usually appeared for me but everyone's situation is different, I'm sure. The OP didn't really make clear what activity she was engaged in or what she was using when these ads appeared but maybe you know better than I.
It's nice to be important but it's more important to be nice.
I highly recommend this response. Ad Blocker is free (Donations appreciated) and is extremely effective at blocking pop-up ads and some categories of on-screen ads. Note, I have no affiliation with this company, I just really like their product.
On several of my browsers I had to get rid of AD Block Plus as It or I found it was hard to manually block 'elements' of certain web pages ie news sites with a large screen blocking "your using a ad blocker" warning. I went with the regular AD Block as it was easier to manually block elements of a web page. But alas the web page creators are getting craftier every day to thwart the ad blockers so I just click close tab and search for a news site that I can read.
Oh and BTW if you AD Block YouTube the video poster will not get monetization money for the video. So keep that in mind if your trying to help out a channel to make money.
"Don't worry about the oil running out, worry about the food running out" Professor Al Bartlett PhD (emeritus 1923-2013)