Greasy Fork is available in English.
Finn Kart-link for Geocaching.com
// ==UserScript==
// @name GCFinn
// @version 1.1.3
// @namespace http://greasyfork.icu/nb/scripts/40538-gcfinn
// @description Finn Kart-link for Geocaching.com
// @include http*://*geocaching.com/geocache/*
// @include http*://*geocaching.com/seek/cache_details.aspx*
// ==/UserScript==
// Copyright (c) 2009-2010 Jostein Austvik Jacobsen
// Edited by Lord Wadar 2017-2021
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
mapLinks = document.getElementById('ctl00_ContentBody_MapLinks_MapLinks');
mapLinksLi = mapLinks.getElementsByTagName('li');
query = mapLinksLi[0].getElementsByTagName('a')[0].href.split("?");
query = query[query.length-1];
lat = null;
lng = null;
for (var i = 0; i < query.split("&").length; i++) {
pair = query.split("&")[i];
if (pair.split("=").length <= 1) continue;
key = pair.split("=")[0];
if (key == "lat")
lat = pair.split("=")[1];
if (key == "lng" || key == "lon")
lng = pair.split("=")[1];
}
if (lat != null && lng != null) {
cacheName = document.getElementById('ctl00_ContentBody_CacheName').textContent;
finnLink = document.createElement('li');
finnLink.innerHTML = '<a href="http://kart.finn.no/?lng='+lng+'&lat='+lat+'&zoom=20&mapType=finnhybrid&markers='+lng+','+lat+',r,'+escape(cacheName)+'" target="_blank">FINN Kart</a>';
mapLinks.prepend(finnLink);
}