How 'free' mobile apps drain your resources

There's no such thing as free -- especially when it comes to smartphone apps! A new study by a team, including an Indian-American engineer, reinforces this conventional wisdom.

"Ads in 'free' apps drain your phone's battery faster, cause it to run slower, and use more data," said William Halfond, co-corresponding author of the study.

The findings of the team will be presented at the International Conference on Software Engineering (ICSE) in Italy in May. The researchers found that apps with ads use an average of 16 percent more energy. That lowers the battery life of a smartphone from 2.5 to 2.1 hours on average.

"A phone's Central Processing Unit (CPU) is like its brain. Ads eat up a lot of that brainpower, slowing it down.

"Apps with ads take up an average of 48 percent more CPU time -- 22 percent more memory use and 56 percent greater CPU utilisation," explained co-researcher Meiyappan Nagappan from Rochester Institute of Technology (RIT), New York.

The team compared 21 top apps from the past year and measured their effect on phones using analysis tools loaded onto a Samsung Galaxy SII smartphone.

Since the ads themselves are content that has to be downloaded, apps with ads cause smartphones to use much more data -- up to 100 percent more, in some cases.

On an average, these apps use around 79 percent more of the expensive network data, the study found. The researchers hoped app developers would take note of this study. "Right now, they're kind of clueless," Halfond said.