In a continuing series of small upgrades to Android Market, Google added ratings distributions for individual apps.

It’s not available on mobile devices quite yet, but the new addition makes it easier for consumers to see how many 5-star and 1-star ratings a particular app received. So if an app has a three-star rating, not necessarily because it’s mediocre but because it’s polarizing for whatever reason, consumers will be able to tell.

Google has gradually been improving the store, most recently with a big overhaul in May that brought new top-grossing charts for apps and new featured slots highlighting specific developers. Before that, Google launched a new web client for the app store back in February that allowed over-the-air downloads of apps.

Android Market has long used a slightly more complex ranking system than Apple’s app store. While Google has never explicitly said what those extra factors are for the ranking algorithms, they could include the long install rate or whether consumers have actually kept the app after downloading it.