This document discusses user-centered practices for engaging with users of existing apps. It recommends using social networks like Facebook and Twitter to find and recruit users. Then using Slack to bring users together into a community for announcements, tasks, and feedback. Google Drive is recommended for openly planning and collaborating. And Google Hangouts can help with user interviews and product demonstrations. A case study of a company's beta program is provided as an example workflow that leveraged these tools to discover issues before launch and build strong user relationships.