Wox is still unstable, and plugin API changes frequently. When it comes stable, we will provide executable file download.
Currently, Wox support using C# and Python to write your plugins. Please refer to Create-plugin page for more infomation.
Share your plugin through WoxPlugins. After you upload your plugin, other uses can download or search your plugin through plugin command (this is a plugin for plugin management, which is one of the default plugins inside Wox).