A study by Flurry Analytics found that apps the average smartphone user spends two hours daily with app, twice the amount of time spent in 2011. While many apps are considered productive, one alarming discover of the report is that 43 per cent of the apps were for games such as the popular Angry Birds.

Apps use almost matched the time spent watching television, while time spent surfing the Web remain flat over the past 24 months.

Besides Angry Birds, the other top-performing apps in Apple are Temple Run: Oz for mobile devices for paid apps, which has a price tag of 99 cents, word game Icomania for free apps and medieval strategy game Clash of Clans as top grosser.

Although many apps are free, upgraded versions still sell and sales of apps is estimated to hit $25 billion in 2013, up 62 per cent from 2012, Gartner said.

Apple store has 800,000 apps available, Google Play has 700,000, Windows has 125,000 and Amazon has 70,000.

While most apps are free or low-priced, on the extreme end, the most expensive is $999.99 which are software for specialised industries such as piano tuning and anesthetics.

Meanwhile, the Data Center of China Internet (DCCI) warned that 35 per cent of Android apps it monitored were allegedly stealing user data that were unrelated to the app's functionality. The study was based on 1,400 apps downloaded by DCCI from various apps vendors.

The agency said 67 per cent actually tracked the users' private data, but 35 per cent collected information not related to the app's use such as location tracking.

The DCCI study came out just a week after China's Ministry of Industry and Information Technology released a white paper that pointed out too much control over the country's smartphone industry by Google through the Android OS and discrimination by the search engine giant against Chinese firms.

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