Applause, a mobile app analytics service that uses more than 60 million app reviews to rate 1 million iOS and Android apps, the company says, has launched the Applause Index, a daily measurement to help retailers and other companies gauge general consumer sentiment about the app world.

The index provides a daily look at how consumers feel about 60 of the most popular iOS and Android apps. It assigns a weighted, cumulative index score for apps on Google Inc.’s Android mobile operating system and Apple Inc.’s iOS. Each app is rated from 1 to 100 based on analysis of user reviews. However, The Applause Index scores for iOS and Android are more than just a sum of the respective apps’ Applause Scores. Individual apps are weighted using a method that takes into account the number of downloads and reviews for each app in the index, the company says.   

The index also includes scores for categories such as lifestyle (which includes retail), gaming and entertainment. The general index and category scores are updated daily, and the list of apps will be formally reviewed each quarter—with some apps being added or removed, depending upon market trends, Applause says.

Friday, for example, the Lifestyle category was down 6.8 points from a day earlier to 6,039.9 for iOS and 9.7 points to 5,091.8 for Android. For iOS, Zappos mobile gets a high score of 90 out of 100 and Groupon comes in second with a score of 89. Poor performers include LinkedIn and Twitter with scores of 36 and 37, respectively. For Android, Dominos Pizza comes in first with a score of 89 and Groupon’s daily-deal app is a distant second with a score of 79. Bringing up the rear is Facebook with a score of 25 and Target with a score of 29.

Over all categories, Calorie Counter and Diet Tracker comes in first for iOS with a score of 95 and restaurant reservation app OpenTable comes in second with a score of 92. For Android, Calorie Counter and Diet Tracker leads again with a score of 88 followed by Dictionary.com with a score of 87.  The overall index score for Friday was up 1.1 points to reach 6,701.8 from 6700.7 a day earlier for iOS and down 2.9 points to 5,413.4 from 5,416.3 a day earlier for  Android.

“The apps economy is driven by how effectively companies connect with users,” says Matt Johnston, chief marketing officer for uTest Labs, which operates Applause and created the Applause Index. “Through app store ratings and social media, those users decide which apps and companies win or lose. The Applause Index fills a need we’ve heard expressed—from business leaders, from journalists and from top-tier analysts—seeking a way to accurately track and measure overall user sentiment and satisfaction in the apps economy.”

Target is No. 34  in the Internet Retailer Mobile 400.