The iOS 9 update that launched Wednesday was anxiously expected by Apple fans. One of the main reasons is that, as of Sept. 16, ad blocking is available for iPhones.

Marco Arment, who co-founded Tumblr and is behind the Instapaper reading app, released ad blocker Peace and saw it become an instant bestseller on Apple's App Store. Peace works with the new Apple ecosystem and filters out mobile ads while blocking unwanted trackers from other apps and webpages.

The trackers are one of the disputed aspects of mobile advertising today, as their data collection and surveillance-like mechanisms make them unpopular among users and developers alike.

"They're unacceptably creepy, bloated, annoying, and insecure, and they're getting worse at an alarming pace," Arment wrote in a blog post. He further added that behavioral tracking was "out of control" when he launched Peace.

If ads can be generally ignored on a desktop monitor, the mobile user is much more vulnerable due to the small display size. Moreover, the ads and trackers directly affect the performance of the phone, slowing down pages and draining battery power. They can easily be used in malicious ways, increasing the risk of cybercrime.

Ad blockers are a blessing for users who want to browse without interruption, but the unspoken truth is that advertisements are vital to some webpages. If ad blockers come to dominate the web, there is a strong chance that some sites will either start asking for subscriptions or simply stop functioning.

The Tumblr co-founder discovered that the huge popularity of Peace may indeed hurt ad-supported content and decided that it was more than he could handle, prompting him to pull the ad blocker from the App Store.

"Achieving this much success with Peace just doesn't feel good, which I didn't anticipate, but probably should have," confessed the developer.

In a sign of good faith, Arment is refunding everyone who purchased his ad blocker and recommends users to get Purify or Crystal, which have fared just as well on the App Store. Peace will continue to be functional, but updating it is out of the question.

"I'm incredibly fortunate to be able to turn away an opportunity like this, and I don't begrudge anyone else who wants to try it," Arment noted.