For the most part this app works great, but sometimes, especially on Yahoo, though I don't see the add, a kind of window or shape of the add does come up and I have to add them myself to get rid of them! But they're are always more everyday back on My Yahoo page! But other than that this is the best add blocker I've found! I read comments of people on YouTube for example complaining about their adds, but I don't see them at all! Same with many other sites!