A HockeyApp developer uses the HockeyApp platform to distribute beta versions of software applications, collect user feedback, and analyze crash reports. They manage the entire lifecycle of testing and deployment, ensuring the app performance and stability. Key tasks include setting up beta testing for new app versions, debugging software issues, analyzing crash analytics for problem resolution, and integrating user feedback into development processes. They also manage distribution lists and permissions for testing teams. In essence, a HockeyApp developer plays a crucial role in app development, testing, and maintenance, contributing significantly to the final product's quality and reliability.