Just a few days after Apple's latest operating system iOS 9 was released with an ad blocking function, apps that promise to limit intrusive and unwanted advertising are leading the company's app store. Apps including Peace, Crystal and Purify Blocker that purport to clean up the mobile browsing experience are among the top five paid downloads. (Peace was removed from the App Store on Friday.)

On Sept. 8, Apple allowed one of the largest ad blocking companies. Adblock Plus, to put its Adblock Browser in its app store. It then strengthened its position the next day when it announced iOS 9 would also include the controversial programs that are infuriating some publishers and advertisers, who claim that ad blocking is cutting into their revenue.