Reference
Leaflet
https://leafletjs.com/

Leaflet is the leading open-source JavaScript library for mobile-friendly interactive maps. Weighing just about 38 KB of JS, it has all the mapping features most developers ever need. Leaflet is designed with simplicity, performance and usability in mind. It works efficiently across all major desktop and mobile platforms, can be extended with lots of plugins, has a beautiful, easy to use and well-documented API and a simple, readable source code that is a joy to contribute to.

Leaflet Color Marker
https://github.com/pointhi/leaflet-color-markers

color variations of the standard leaflet markers

Leaflet Heatmap.js
https://www.patrick-wied.at/static/heatmapjs/plugin-leaflet-layer.html

A plugin to create a heatmap layer for Leaflet.

Leaflet Geometery Util
https://github.com/makinacorpus/Leaflet.GeometryUtil

Leaflet utility function on geometries

Leaflet Arrowheads
https://github.com/slutske22/leaflet-arrowheads

A small plugin for leaflet to quickly draw arrowheads on polylines for vector visualization

Bootstrap 4
https://getbootstrap.com/docs/4.0

Get started with Bootstrap, the world’s most popular framework for building responsive, mobile-first sites, with BootstrapCDN and a template starter page.

Mapbox
https://www.mapbox.com/

Maps and location for developers Precise location data and powerful developer tools to change the way we navigate the world.