Apple has made a small but significant change to iOS app listings on its App Store, adding a prominent "Offers In-App Purchases" line for freemium apps on its store.

The new tagline is currently only appearing in the desktop version of the App Store that sits within iTunes. For now, it's not shown in the iOS App Store app, nor does it appear on webpages for iOS apps.

Update: Over the weekend, after this story was initially published, the warning message went live on the iOS App Store app.

Apple confirmed to The Guardian that the message is a new addition to the App Store. Its location – directly below the icon and "Free" button on each app's page – makes it even easier for people to identify that an app uses in-app purchases (IAP) before downloading it.

A big change? Not as such: there is already a space on freemium apps' pages showing "Top In App Purchases", which lists the most popular purchases made within them. Even the least tech-savvy iOS users would be likely to draw the right conclusion after spotting it.

That said, the addition of a separate "Offers In-App Purchases" message is still significant. For example, as metadata for iOS apps, it could be the key to a future settings change that enables users (parents, in particular) to easily filter out apps with IAP when browsing the store.

The message may also be a response to the negative publicity in recent months around children running up huge bills buying virtual items within iOS apps without their parents' knowledge.

Examples include one British boy who spent £1,700 playing Zombies vs Ninja, and another who bought £980 worth of virtual donuts in The Simpsons: Tapped Out. In both cases, Apple refunded the parents.

Apple has also recently settled a US lawsuit over in-app purchases made by children, agreeing to spend as much as £66m refunding parents whose kids spent without asking them.

Adding an extra notification that apps contain IAP to the desktop App Store isn't a solution to this problem, not least because as Apple's services boss Eddy Cue explained at the company's iPhone 5 launch in September 2012: "More than two thirds of our [iTunes] downloads now come directly for iOS devices."

There is a spirited debate within the apps industry about the use of IAP within children's apps, as shown by the often-heated comments on The Guardian's article on the subject earlier in March, as well as a follow-up post giving parents advice on how to restrict IAP on their devices.

The gist of the debate was that parents must take responsibility for knowing what apps their children are using and how IAP settings work; that developers of children's apps must be responsible in their use of freemium (this, at a time when it's increasingly common for children's games on iOS to offer IAP of up to £69.99 at a time); and for Apple to shoulder some of the responsibility for educating parents about all this.

Making it clearer which apps use IAP is a step in the right direction on the latter front. More may follow at Apple's WWDC developer event this summer, when the company is expected to unveil its iOS 7 software.