How would that work? I mean, blocking ads by yourself... It's a bit useless, isn't it? You'd have to take off ads and pop-ups manually by clicking multiple cross-shaped icons. Maybe, you're refering to decide what kind of ads you would like to see but I think that'd not be possible, since there are all types of ads and they show up randomly. If you want to decide what pages may show ads; there're adsblocks that allow you to whitelist pages. For example, Opera ad blocker or Enhacer for Youtube (as the name says, this works only for youtube; allowing you to decide what channels can show up ads and other features)