It has been an intense week for freemium game developers on Apple’s iOS platform — and the drama has yet to be resolved, as we’ve been covering over on Inside Mobile Apps. By last Sunday, a number of service providers for iOS developers were reporting odd changes in Apple’s top apps rankings in its iTunes App Store.

Some apps rose to the top after months of lower rankings for no apparent reason, while others were buried. Facebook, for example, suddenly became the most popular top free application on iOS despite not having made any recent changes and not having been #1 since at least July 2009 — which suggested that daily and monthly usage could be newly important factors. At the same time, some games lost their ranking spots. But as of Tuesday, the rankings changed back to favoring new games that apparently had high downloads rates. It’s not clear what factors Apple is considering now in the rankings.

Meanwhile, developers began receiving rejection notices starting late last week from Apple for new submissions that contain offer walls where users can get rewards for downloading other developers’ games. The rejection notices argue that offer walls have an “excessive influence” on the chart ranking.

Apple has been mum and many service providers have also gone quiet as they try to come to up with solutions. We’ll be covering these changes as we learn more, over on Inside Mobile Apps.

In the meantime, we’ve been leading coverage of the issues over the past week. In case you’ve missed it, be sure to check out the following articles, in chronological order:

• Apple May Have Tweaked App Store Ranking Algorithm, Making Downloads Matter Less
• Facebook’s iPhone App Vaults to #1 on Suspected Ranking Algorithm Changes
• Apple Appears to be Cracking Down on Incentivized Installs
• Odd Rankings Fluctuations Continue in Apple App Store
• Mobile Game Developers Grapple With Apple Crackdown on Incentivized Installs
• Pocket Gems’ Tap Pet Hotel Scales to #2 on iOS Free & Grossing Charts, Offer Wall Conspicuously Absent