[HTML/JS] Maps in Desktop App

I am looking to make an app that has an updating location map in a small portion of the window. I was going to use Google Maps, but I don't want users to have to register for an API key. I was going to use an iFrame of Here maps, but there are too many things like search bars and other options in the way. Is there a free to use, no API key based option for a map? I am fine reloading the map section every 15 seconds or so, so it can be an iFrame, but a legitimate JS option would be cool. I am just using the HTML/JS as an overlay on the UI.