This installation failed...
Craft's help page is woefully unhelpful about installing the plugin manually for sketch, and it only reads "We don't recommend manually installing the Craft plugins for Sketch." without any additional steps, fortunately the good people behind Invision made the plugin URL available to reverse engineering :)
- Download craft-sketch.zip and unzip it (doubleclick)
- Go to ~/Library/Application Support/com.bohemiancoding.sketch3/Plugins and drag in the Panels.sketchplugin
- Go to ~/Library/Application Support/com.bohemiancoding.sketch3/Panels and drag in the Data.sketchpanel, Duplicate.sketchpanel, Library.sketchpanel, and Sync.sketchpanel
- Launch Sketch and verify it has been installed under Sketch plugins.
Enjoy your new plugin?