The integration of the U.S. National Grid (USNG) coordinates in online web mapping systems has only been partially implemented on a variety of web mapping pages. When not in possession of USNG standardized printed map products, one of the most difficult things to do is to take a USNG coordinate and quickly produce a basic, readable map, or visa versa: take a basic map or address and obtain a USNG coordinate.
Due to the Google Maps billing changes coming in summer of 2018, the demonstration site is likely to stop working. Details about the changes can be found here: https://developers.google.com/maps/billing/important-updates
Contributors include Mike Dolbow and Sean Gutknecht. A demonstration page can be used at http://mmdolbow.github.io/usng-gmap-v3/