Apple is bringing ads to the App Store and expanding its app subscription program, the company announced ahead of its Worldwide Developers Conference next week.

The advertising program, called "Search Ads," will arrive on the US version of the App Store this fall, sporting a light blue background to distinguish its listings from regular search results. Developers will be able to pay to to promote their apps by having them listed at the top of a relevant search. Customers can then download the app with a single tap directly from the search results.

Apple says an ad will only display if it is relevant to the search query, meaning developers can't pay extra to include their app alongside more search terms. In addition, an ad for a specific app will only show up if the user doesn't already have it installed.

Targeting features will allow developers to find potential users by harnessing Apple's data on their demographic profile and device's location. But Apple says Search Ads will follow the same privacy protocols it has developed for other services. That means ads can't track users' App Store searches, collect individual data, or be shown to minors under age 13.

The introduction of ads is the latest tweak to how app store results are displayed, following a change last fall that saw Apple's search algorithms switch to partial keyword matching for more relevant results. Developers can opt in to Search Ads now, and a beta trial will go live this summer.

Meanwhile, Apple's app subscription program will expand to all app categories starting this fall. Originally intended for apps offering newspapers, educational courses, or audio or video libraries, Appe says that many users see value in ongoing subscriptions for a broader range of services.