If the app does not come with your Firefox OS phone, I'm afraid you're out of luck, because the Firefox Marketplace says "The app requested is not public."

Hi Ronson,

I understand you are having trouble locating your Here Maps application.

You may also try alternatives to Here Maps, available in the Firefox Marketplace:

• https://marketplace.firefox.com/search?q=maps

Thanks, - Ralph

Here Maps is not available in Firefox Marketplace anymore. But there's a navigation app by tomtom: https://marketplace.firefox.com/app/maps-online-1