Flurry said that the developer “middle class” – sitting outside of the top 25 most popular apps, but ahead of the “long tail” of unranked titles – has a greater earning power now than in 2012, as the proportion of revenue earned by the top titles decreases.

Comparing an estimate for the full-year 2012 with its numbers for 2010, the company said that “each position in the top 100 is more valuable now, which makes sense because the market has grown overall”.

It also noted that, moving down the ranks, the drop-off is now less sharp than before, starting to stabilise after the top five apps, with a “high, gently sloping plateau” through to 80th position, at which point it settles slightly above the 2010 level.

Flurry observed: “The age of middle-class app developer has arrived. In this economy not only are the rich getting richer, but so too are the poor, and gaining on the rich.”

Excluding advertising, the company said that 15 percent of revenue will be earned by the top 25 apps in 2012, with 17 percent earned by the titles in 26th to 100th position, and 68 percent going to the remainder.

Compared to 2010, this marks a decrease from 28 percent for the top 25 apps and from 27 percent from the 26th to 100th positions – meaning that the “rest” category has increased its share from 45 percent.

Shifting to a year-on-year analysis, Flurry said that Android and iOS apps will generate US$8.7 billion in revenue (including advertising) this year, up 60 percent when compared with the US$5.4 billion achieved in 2011.

The fastest growing revenue stream is advertising, which is set to double in value from US$980 million to US$2 billion in 2012, increasing its share of the total from 18 percent to 23 percent.

In-app purchasing and premium app revenue will also see robust growth, increasing by 50 percent from US$4.5 billion to US$6.7 billion, with its share of the total decreasing from 82 percent to 77 percent.