Which Apps Have Privacy Policies? - An Analysis of Over One Million Google Play Store Apps

Smartphone app privacy policies are intended to describe smartphone apps’ data collection and use practices. However, not all apps have privacy policies. Without prominent privacy policies, it becomes more difficult for users, regulators, and privacy organizations to evaluate apps’ privacy practices. We answer the question: “Which apps have privacy policies?” by analyzing the metadata of over one million apps from the Google Play Store. Only about half of the apps we examined link to a policy from their Play Store pages. First, we conducted an exploratory data analysis of the relationship between app metadata features and whether apps link to privacy policies. Next, we trained a logistic regression model to predict the probability that individual apps will have policy links. Finally, by comparing three crawls of the Play Store, we observe an overall-increase in the percent of apps with links between September 2017 and May 2018 (from 41.7% to 51.8%).