The launch of Apple’s iOS6 platform has resulted in the visibility of apps changing significantly in the App Store rankings, with observers also highlighting other changes that have been met with disapproval.

Some apps that were prominent in the store rankings before the update have suffered, while others have benefited, fuelling speculation that the ranking algorithm has changed.

Apps analytics service apptrace said there a number of reasons why app rankings have altered that suggest the ranking algorithm itself hasn’t been modified.

Apple promoted its own apps more heavily following the update, with apps featuring the new Passbook functionality being particularly visible. Updates to popular apps to coincide with the release of iOS6 also distorted the rankings, along with the Genius function replacing Categories.

“The effects witnessed now are due to various new AppStore features and cannot be decisively linked to any change of the algorithm itself”, said Paul Muller, co-founder of apptrace parent company adeven.

Apps analytics firm Distimo said its data doesn’t suggest the algorithm has been changed. Firstly, the correlation between downloads and rankings is as accurate was it was before the change, and secondly there was little change in the volatility of the rankings once Apple pushing its own apps and those including the passbook functionality was taken into account.

Game developer Lightwood Games pointed out a number of other issues with the updated App Store on its company blog, with MD Chris Newman claiming that the iOS6 version of the App Store “is a disaster”.

The first issue is that there is no longer the ability to sort apps by release date, something particularly problematic for small developers, who are trying to push new apps.

In addition, the ability to view a list of search results has been replaced with a single app view and scrolling mechanism, which means it takes longer to find relevant apps and gives greater exposure to titles that appear first on searches.

However, Distimo said that the impact of the changes in the App Store interface require more long-term analysis for conclusions to be drawn.