Development tools for Zephyr on STM32Workbench for Zephyr: VS Code extension to set up, build, flash and debug Zephyr applications on STM32.Devicetree manager: browse, edit and visualize Zephyr devicetree, STM32CubeMX-like for Zephyr.
OS/X support is expected to get through in the coming months; we are now finishing to test the Linux support, that will be public really soon now. OS/X will probably be available in beta in about a month, so stay tuned.