Tapjoy&39's favor system inside an iOS application. Users can download and launch applications to gain in-game currency.

Following murmurs of Apple making changes to its App Store ranking algorithms to devalue the effect of downloads alone, new claims have been made that Apple is actively rejecting applications that include features designed to boost installations.

A letter sent to developers by Tapjoy, a company that runs a program that promises to "drive 100,000-plus app installs daily" as well as grow revenue by 100 percent, said that an unspecified number of applications making use of the promotional program were being rejected by Apple.

"To be clear, there is no new Apple policy that we are aware of," wrote Mihir Shah, Tapjoy's president and CEO, in the letter picked up by VentureBeat. "It seems there may be a new interpretation of the existing 3.10 clause, which is a bit surprising, as Tapjoy, AdMob, iAd, Flurry, W3i and others all power various forms of app install advertising."

The 3.10 clause Shah is referring to is part of Apple's App Store Guidelines, which highlight manipulating and cheating of user reviews and chart ranking within the App Store, threatening to ban offenders:

Shah said if that was the case, it was a "misconception" by Apple about the company's pay-per-install program, as well as others like it.

"We believe there are significant benefits to the advertiser (only pay for what you get), the publisher (monetize users who otherwise wouldn't pay), and perhaps most importantly to the users, who not only get to discover new, exciting applications, but receive what is essentially a coupon for ad-funded virtual currency inside one of their favorite apps," Shah wrote. "All of this, of course, adds up to value for Apple as well, by creating a viable and thriving ecosystem."

Despite Tapjoy's claims, not all these companies are convinced Apple has made sweeping changes to its reviews system to bar such features from applications. W3i, a company that offers a similar pay-per-install advertising program, would be a likely target. But company spokesman Ryan Ruud told CNET that "it's too early for us to speculate on alleged rejections or changes to Apple's policy."

Like Tapjoy, W3i's pay-per-install advertising program gives developers and publishers a way to promote applications through its network of participating applications that offer in-game points and rewards to users. The company would not say how many iOS applications make use of the system, but based on the promise of being able to "crack" the Top 25 app lists on multiple platforms, and claims of pushing more than 1.5 million total application installs per day, it's safe to say the number is high.

Apple did not immediately respond to a request for comment on whether it was barring applications that made use of such features. CNET also reached out to Flurry, Google-owned AdMob, and Tapjoy for more information about the scale of any rejections for applications that make use of the two systems.