In a bid to curb app ranking scams, Apple appear to have tweaked the App Store's ranking algorithm causing some chart favourites to plummet as many as 300 places.

Chinese news site Netease Tech spotted that a number of Chinese-made apps had seen major shifts around the App Store charts over the past week.

Many companies have been affected by the alleged alterations including Renren, Buding Movie Tickets, Yi Xia and Dangdang.

Particularly impacted has been Chinese studio KoramGame, whose title Feng Wan Three Kingdoms dropped from fourth place to 335th.

Win some, lose some

In light of these changes, a number of non-gaming apps including those from Chinese banks ICBC and CCB, 360Buy, Huofar, Pulse Business Cards, Youdao Cloud Notes, and Tencent's QQ Mailbox have all jumped up at least 100 spots.

Social network Douban saw its own apps shift places dramatically up and down the charts. Its Dujiao LBS app sunk whereas its Douban FM social music app jumped from 202nd to 126th place.

This would chime with a move to make daily activity a more important part of the ranking algorithm; something that Google has long stressed for its Play app store charts.

Stricter policing

Competition to rank highly on the App Stores charts has seen some developers resort to third party services including paid-for-five-star reviews and even negative ones aimed at competitors.

Combined with bot farms and other hacking activity, it's rumoured that as much as ten percent of the apps in the Chinese App Store's top 100 are cheating the system in some way - something many legitimate developers have been asking Apple to fix for many months. 

[source: Netease Tech]