Background:
Smartphone has become a main part of our daily lives, and its impact on human behavior has been extensively studied. In Korea, 8 out of 10 people have their own smartphone and download 48 applications on average to get and share information. Recently, tobacco marketing prevails in the smartphone application but there is limited research on this area. This study investigated the prevalence of pro-smoking applications (apps) in Korea in order to understand the current status and potential risks.

Methods:
From mid-June to early July 2017 (for 3 weeks), this study searched the Google Play store for pro-smoking apps. 8 keywords (cigarette, e-cigarette, nicotine, cigar, hookah, etc) were used to identify tobacco related apps. Apps achieved a top 100 ranking for each keyword then classified and analyzed based on apps name, retailer category, content category, number of downloads, publisher names, and content rating.

Results:
Among a total of 675 apps identified for 8 keywords, 511 were analyzed for this study to avoid duplication. Although some anti-smoking apps (n=119, 23.3%) provided information on health effects of smoking or smoking cessation, majority were classified as pro-smoking apps (n=392, 76.7%) containing information about how to make tobacco, advertisement on tobacco products and shops, places where smoking is allowed, game to simulate smoking behavior or to run tobacco company by selling cigarette, and smoking advocacy. More importantly, 99.7% of these pro-smoking apps were rated as minors under 18 year-old can use them without any restrictions.

Conclusions:
Pro-smoking apps prevail in the market while there is no restriction on access, install and use. Considering its cross-border characteristics, this would pose great challenge against tobacco control policies where smartphone use is increasing. Strategic approach to deal with novel tobacco marketing tactics needs to be developed with special attention to youth population.