What's Inside My App?: Understanding Feature Redundancy in Mobile Apps

As the number of mobile apps increases rapidly, many users may install dozens of, or even hundreds of, apps on a single smartphone. However, many apps on the same phone may contain similar or even the same feature, resulting in feature redundancy. For example, multiple apps may check weather forecast for the user periodically. Feature redundancy may cause many undesirable side-effects such as consuming extra CPU resources and network traffic. This paper proposes a method to identify common features within an app, and evaluated it on over four thousand popular apps. Experiments on a list of apps installed on actual smartphones show that the extent of feature redundancy is very high. We found that more than 85% of user smartphones contain redundant features, while in extreme cases, some smartphones may contain dozens of apps with the same feature. In addition, our user surveys found out that about half of the redundant features are undesirable from the end users' perspective, which indicates that feature redundancy has become an important issue that needs to be investigated further.