AppAnnie, the app metric tracker, has released its quarterly market index to reveal how mobile app sales are evolving recently. 

A look at the results reveals that the BRIC countries, especially Brazil, Russia, and China, are rising up the ranks; worldwide iOS App Store downloads were driven by strong growth in China and Russia, but Google Play- which grew more than iOS over the past quarter, was driven by an increase in downloads in Brazil and Argentina. China moved up two spots to become the third highest grossing country on the iOS App Store.  

Game developers in the Middle East, while they may want to consider these rising markets, will also be interested in the most popular categories worldwide. Here, things are staying the same: game apps are still #1, both in terms of downloads and revenue, in both the iOS App Store and Google Play.

According to AppAnnie, games accounted for about 40% of downloads and for about 70% and 80% of revenue, respectively, on the App Store and Google Play, during Q3 2013. However, games are losing a bit of ground compared to other rising categories when it comes to revenue; revenue from games on the iOS App Store dropped from 75% during Q2 2013 to 70% during Q3 2013, as a result of growth in social networking and navigation apps. 

Apps in Social Networking, (or Communication, as it's called on the Google Play), is a sector to watch, not just because it's maintaining second place in terms of both revenue on the two stores, but also because of the fierce competition. 

Only one category has newly entered the top five this quarter: Education. For startups in the Arab world building in the EdTech sector, the opportunity for a global audience could be promising.