San Francisco, May 27 (IANS): An iOS app that forced users to leave a positive rating before using it managed to get past Apple's App Review process, though it has since been removed from the App Store.

The app, named UPNP Xtreme, purported to let users stream videos to their TV. However, as soon as the app opens after installation, it demands a review before it even functioned, Apple Insider reported.

As spotted by the app developer and anti-scam advocate Kosta Eleftheriou, the app would open a review dialog box as soon as it opened. However, the box could not be dismissed without leaving a review that was between three and five stars.

The review behaviour directly violates Apple's App Store guidelines, which bar developers from "showing a request review immediately when a user launches your app".

More than that, Apple's review API wouldn't allow developers to force leaving a review, so the developer of the scam app appears to have side-stepped the standard developer tools.

In a subsequent tweet, Eleftheriou said the odd functionality was the result of a "trick" that is "extremely easy for any developer to do".

According to Eleftheriou, the developer of the fraudulent app has more than 15 million downloads and reportedly makes millions in revenue.

This isn't the first scam app Eleftheriou has discovered -- the app developer has publicized a slew of scammy apps in the past while vocally criticized Apple's App Review process.

Back in March, Eleftheriou sued Apple for allegedly enabling the scam app problem.