To install, "Download Zip" to the right, and double click the .sketchplugin file.
Name Artboards and Draw Slice
Goes through each artboard and creates a text label where the artboard name sits so it is visible when exporting with slices. It also draws a slice around all visible content (toggleable).
If you move / change artboard names, just re-run the plugin and it will replace the old 'Artboard labels' group with a new one! Careful not to have other groups with the same name — it will be erased.