Enterprise users are increasingly accessing our Java applications with mobile devices. Native applications often provide a better user experience on mobile devices than web applications. But developing two different applications for iOS and Android is expensive and time-consuming. Cross-platform frameworks promise salvation: Mobile, web, and desktop front-ends with one codebase. I think Google’s Flutter is the best cross-platform option for Java developers. But can Flutter deliver? I’ve developed native applications for iOS and Android with Flutter and put them in the app stores. Based on my experience, I describe the advantages of Flutter for Java developers, but also typical problems and their solutions. With an example application, I demonstrate how mobile, web, and desktop front-ends can succeed with one codebase—and what the limitations are.