Many automated test generation techniques have been proposed for finding crashes in Android apps. Despite recent advancement in these techniques, a study shows that Android app developers prefer reading test cases written in natural language. Meanwhile, there exist redundancies in bug reports (written in natural language) across different apps that have not been previously reused. In this paper, we propose \emph{collaborative bug finding}, a novel approach that uses similarities between different Android apps for finding relevant bug reports that help in the discovery of new bugs. Given an app under test, our approach uses interactions between programmers for deriving specialized test scenarios. We design three settings with varying degrees of interactions between programmers where each setting emulates a different real-world scenarios. Our studies of the first two settings in a software testing course show that collaborative bug finding helps students who are novice Android app testers to discover 17 new bugs. However, students admit that searching for relevant bug reports could be time-consuming. Based on students’ feedback, we introduce Bugine, an approach that automatically recommends relevant GitHub issues for a given app. Our results show that Bugine is able to find 34 new bugs. In total, collaborative bug finding helps us to find 51 new bugs, in which five have been confirmed and seven have been fixed by the developers. These results confirm our intuition that our proposed technique is useful in discovering new bugs for Android apps.