Mobile apps face strong pressure for fast and reliable updates. Continuous Integration (CI) helps automate builds, tests, and releases, but its impact on mobile development remains underexplored. Despite the widespread use of CI, little is known about how it affects development activity, release speed, and user-facing outcomes in mobile projects. Existing studies mostly focus on CI adoption in general-purpose software, providing limited insight into mobile-specific dynamics, such as app store visibility and user engagement. In this paper, we analyze open-source Android apps to (1) compare CI adopters and non-adopters, (2) characterize adoption patterns using activity and bug metrics, and (3) assess pre/post adoption changes and user-facing outcomes. We observe that CI adopters are larger and more active, with faster and more regular releases. CI adoption is concentrated in integration- and reliability-intensive categories (e.g., finance and productivity) and is associated with higher Google Play Store engagement (more downloads and reviews) without lower ratings. Overall, CI adoption aligns with practices that support sustained delivery, higher project visibility, and stronger user engagement in mobile ecosystems.