When the folks behind “Hamilton” wanted to build an app for the smash musical quickly last year, they turned to a little-known mobile software framework called Flutter that Google quietly previewed ...

Google says two million developers have used its Flutter user-interface (UI) framework for building apps targeting mobile, desktop, and the web since declaring it production ready at Google I/O 2018.

There’s a lot to be said for tools that make it easy to target multiple platforms from a single codebase, reducing the load on developers and increasing the reach of your applications. Microsoft’s ...