Flutter's templates, tooling, and runtime are currently primarily optimized for the use case of creating a new mobile application from scratch. However, several developers have expressed an interest in making it easier to add one or more Flutter "screens" to existing Android and iOS apps.

The present bug tracks reduction of general friction developers encounter when trying to accomplish this integration of Flutter into existing apps.

The detailed work for this effort is tracked in a number of more detailed issues:
https://github.com/flutter/flutter/issues?q=is%3Aopen+is%3Aissue+label%3A%22a%3A+existing-apps%22

The initial documentation for the preview support is available on our Wiki:
https://github.com/flutter/flutter/wiki/Add-Flutter-to-existing-apps