The tobacco industry is now using smarphone apps -- a medium that has global reach, including to children -- to promote its products, warn researchers in Tobacco Control.

The availability of pro-smoking content in app stores seems to be violating Article 13 of the World Health Organization Framework Convention on Tobacco Control (WHO FCTC), which bans the advertising and promotion of tobacco products in all media, say the authors.

In February 2012, they searched two of the largest smartphone app stores (Apple and Android Market) for the availability of English language pro-smoking apps, using the keywords: 'smoke,' 'cigarette,' 'cigar,' 'smoking' and 'tobacco.'

Pro-smoking was defined as any app that explicitly provided information about brands of tobacco, where to buy products, images of brands and cigarettes, and any trigger cues for smoking.

They found 107 pro-smoking apps. Some contained explicit images of cigarette brands; others images that resembled existing brands. Some allowed the user to simulate smoking.

In all, 48 were classed as smoking simulation; 42 as shop/brands; nine were classed as cigarette battery apps, which depicted a burning cigarette to show the amount of battery left; six as background wallpaper; one as advocating smoking; and one as providing information on roll-ups.

Forty two of the apps were from the Android Market and had been downloaded by 6 million people. The most popular Android apps were those for smoking simulation.

The authors acknowledge that some of the simulation apps claim to aid smoking cessation, although there is no evidence to show that this approach works. But these were included because they either resembled cigarette brands or because they were published under the headings of 'entertainment,' 'games,' or 'lifestyle.'

The authors point out that in 2011, the number of mobile phone subscribers had reached just under 6 billion -- 2.5 times more than the total number of internet subscribers -- and that smartphones account for around one in three handsets in the developed world.

Young people are particularly vulnerable, because of the popularity of smartphones among this age group, and the appeal of the apps, say the authors.

They cite the UK telecoms regulator Ofcom, which, in 2011, found that almost half of the teens it surveyed owned a smartphone, and an analysis by the Nielsen Company, which showed that in the second quarter of 2010, US teen mobile phone subscribers had increased their download app frequency to 38% from 26% the previous year.

Downloading apps from the Apple store does prompt messages about age restrictions when the content is smoking or classed as 'high maturity,' but there are no such warnings in the Android Market, say the authors.

"Pro-smoking content, including explicit cigarette brand images, is promoted in smartphone apps, which are reaching millions of users, including teenagers and children. App stores need to explore ways of regulating this content," say the authors.

And they add: "App stores have a moral (and arguably) a legal responsibility to ensure they have the infrastructure to comply with WHO FCTC and other laws restricting advertising of tobacco to minors."