Uncovering and explaining how our digital world is changing — and changing us.

Marco Arment, a developer and blogger who had been one of the most prominent advocates of ad blocking, has pulled his best-selling ad-blocking app from Apple’s App store.

“Just doesn’t feel good,” Arment titled a post explaining the move, which came just three days after his “Peace” app launched. On Wednesday, Apple’s new iOS9 software allowed developers to sell “content-blocking” software.

Arment’s post is pretty concise, but here’s an even shorter version: Arment says he felt bad that his app automatically blocked all ads, and didn’t offer a default way to protect “many who don’t deserve the hit.”

This is an about-face from yesterday, when Arment argued that this blunt approach wasn’t ideal, but was his best option. “It’s uncomfortable, but I’d rather be consistent and fair.”

Yesterday, Arment’s $3 app was the top-ranked app on Apple’s app store, which doesn’t necessarily mean it was selling more units than any other app (Apple doesn’t disclose its formula for app ranking), but developers believe that velocity — how quickly the app’s popularity has increased — is one of the factors.

The app also drew criticism from fellow blogger and ad-blocking advocate John Gruber, who argued that his site’s ads shouldn’t be blocked because he “put[s] readers’ interests first, and only publish[es] the sort of ads and sponsorships that [he] would want to be served.” Gruber was apparently surprised that Arment’s ad blocker and others didn’t include his site on a “white list” of sites that could still display ads.

https://twitter.com/gruber/status/644409410048106496