Although not new technology, I just got my hands on a new Sperry Volt Sensor model VD 6504. Ruggedly made and it works like a charm. A quick search found them available at Amazon.com for $15. If you work on electricity around the house or on the dock or your boat equipped with shore power, you want this inexpensive tool.
It works just as shown in the photo here by plugging the plastic tip into an AC socket and looking for the red glowing light and hearing a rather obnoxious chirping sound that let’s you know loud and clear that AC voltage is present at that terminal.
These units will track through insulation on wire too, so tracing live AC current as it moves through your shore power system is as easy as pushing the tool’s activating button and walking it along the outside of cabling. Simple, inexpensive and helpful. This one’s going into Ed’s Tool Box.