The most notable addition to the SDK in the upgrade is a command line interface (CLI) for Windows, Linux and macOS. Using the CLI, developers can build apps and clock faces using their own code editors and version control systems. To date, it has been necessary to use an online tool called Fitbit Studio, which Fitbit launched last fall, but many developers have requested a CLI so that they can use their own tools.
The CLI includes a full toolchain for app and clockface development. An interactive shell allows for building, installing, screenshotting, and logging. By using tools such as Microsoft VSCode, which allow the exeuction of a terminal shell directly within a code editor, developers will be able to perform key development functions without leaving their preferred editors.
According to Fitbit, there are more than 20m active Fitbit users and since it launched Fitbit Studio, developers have used its tools to create over 1,000 apps and clockfaces for its Ionic and Versa smartwatches. The company says it's looking forward to seeing how developers use its new tools, and what they build with them.