Benjamin Mayo, writing for 9 to 5 Mac:

With iOS 9, Apple has added a special case of extension for ad blockers. Apps can now include ‘content blocker’ extensions that define resources (like images and scripts) for Safari to not load. For the first time, this architecture makes ad blockers a real possibility for iOS developers to make and iOS customers to install and use.

Could this also open the door for content filtering apps which prevent children from visiting adult websites? iOS has this feature built-in, but it doesn’t offer any options for what type of content is blocked.