Some 15 per cent of apps are in the “Superstar” category, being in the top third in terms of both users and rolling customer retention – but 17 per cent are in the “Black Hole” category, being in the bottom third for both, according to a study from Flurry.

The company said that Superstar apps are best positioned to generate revenue, regardless of monetisation model. Titles in the Black Hole could be “relatively new apps that are still trying to establish a user base, old declining apps, or apps that are of poor quality”.

The company identified two other notable categories: Red Dwarfs, which have a relatively small user base but are doing well on retention, meaning they are likely to be successful long-tail apps; and Shooting Stars, which have a lot of users, but may fade quickly due to poor retention.

Unsurprisingly, the amount of time spent using high-retention apps is greater than for low-retention titles. For example, Superstar apps have almost twice the number of monthly minutes per user than Shooting Star apps, at 98 minutes versus 50 minutes.

However, apps with large numbers of users also fare better in terms of average time per user per month. Flurry said that while this is statistically significant, the correlation between time per user and retention is stronger.

Flurry concluded that the results imply that developers “need to make retention their top focus”, and that with the ability to shape and modify the app experience, “it’s within their control”.

In addition, the association between retention and time spent can be beneficial for developers in terms of in-app purchases and advertising.

And the more useful an app, the better it retains users, making acquisition efforts more efficient – “acquiring aggressively before an app retains well and be a costly mistake”.

Flurry ranked apps with more than 32,000 active users as the top third, with more than 8,000 needed to join the top two thirds, and more than 1,000 needed to qualify – in order to eliminate apps that are being tested or no longer supported.

Retention was based on users who first accessed an app during November 2012, and then used it at least once more over the next 30 days. To be in the top third, an app needed at least 37 per cent retention rate, with 22 percent the cut-off for the next third.

Flurry Superstars