Apple is rolling out search ads to its App Store in the UK, which it says will help small developers boost download numbers.

Paid ads have appeared in the App Store on iPhones and iPads in the US since September last year, and tomorrow (April 25th) they are going live in three other major English-language markets for Apple - Australia, New Zealand and the UK.

The system is designed to be as unobtrusive as possible so as not to greatly disrupt the user experience, with one paid ad appearing per search query, which is clearly labelled.

Apple says the ads enable independent developers to use data such as gender, age and location to refine their audience. The system operates on a pay-per-click basis.

It has also made some changes to the Search Ads Dashboard, including the launch of a new Duplication feature. This lets developers replicate settings and keywords for current ads to be used in campaigns aimed at new audiences.