  The competing nature of the app market motivates us to shift our focus on
apps that provide similar functionalities and directly compete with each other
(i.e., peer apps). In this work, we study the ratings and the review text of
100 Android apps across 10 peer app groups. We highlight the importance of
performing peer-app analysis by showing that it can provide a unique
perspective over performing a global analysis of apps (i.e., mixing apps from
multiple categories). First, we observe that comparing user ratings within peer
groups can provide very different results from comparing user ratings from a
global perspective. Then, we show that peer-app analysis provides a different
perspective to spot the dominant topics in the user reviews, and to understand
the impact of the topics on user ratings. Our findings suggest that future
efforts may pay more attention to performing and supporting app analysis from a
peer group context. For example, app store owners may consider an additional
rating mechanism that normalizes app ratings within peer groups, and future
research may help developers understand the characteristics of specific peer
groups and prioritize their efforts.
