I have a cheap quad core 9 inch tablet running Android 4.4.2. I use it for research while I write on my PC. The trouble is while I'm reading I am periodically interrupted by spontaneous pop-up ads (mostly for games). Is there a sure way of getting rid of these? I typically use Google Chrome as a browser. However I downloaded one called "Free Adblock" which does block ads but lacks some of the features I like to use in Chrome.