Google Map Integration in Salesforce using Javascript

Google Map can easily be integration with VF page using few standard libraries provided by Google and Salesforce.

Below is an example, where I am integration with Google Map to display few nearby Accounts from my current position or a default position.

VF Page:

<apex:page sidebar="false" showheader="false" recordSetVar="clubs" controller="ShowNearByPlaces">
    
    <script type="text/javascript" 
        src="https://maps.googleapis.com/maps/api/js?key=AIzaSyAVrfZm7_NhbLjHrFPdl242BYV1PBmDPqs&sensor=false"> 
    </script>
        
    <!--Setup the map to take up the whole window-->
    <style>
        html, body { height: 100%; }
        .page-map, .ui-content, #map-canvas { width: 100%; height:100%; padding: 0; }
        #map-canvas { height: min-height: 100%; }
    </style>
    
    <script>
        function initialize() {
            var lat, lon;
              
             // If we can, get the position of the user via device geolocation
             if (navigator.geolocation) {
                 navigator.geolocation.getCurrentPosition(function(position){
                     lat = position.coords.latitude;
                     lon = position.coords.longitude;                    
                     
                     // Use Visualforce JavaScript Remoting to query for nearby clubs      
                     Visualforce.remoting.Manager.invokeAction('{!$RemoteAction.FindNearby.getNearby}', lat, lon,
                         function(result, event){
                             if (event.status) {
                                 console.log(result);
                                 createMap(lat, lon, result);           
                             } else if (event.type === 'exception') {
                                 //exception code          
                             } else {
                                            
                             }
                          }, 
                          {escape: true}
                      );
                  });
              } else {
                  // Set default values for map if the device doesn't have geolocation capabilities
                    /** Pune, India **/
                    lat = 18.516726;
                    lon = 73.856255;
                    
                    var result = [];
                    createMap(lat, lon, result);
              }
          
         }
    
         function createMap(lat, lon, clubs){
            // Get the map div, and center the map at the proper geolocation
            var currentPosition = new google.maps.LatLng(lat,lon);
            var mapDiv = document.getElementById('map-canvas');
            var map = new google.maps.Map(mapDiv, {
                center: currentPosition, 
                zoom: 13,
                mapTypeId: google.maps.MapTypeId.ROADMAP
            });
            
            // Set a marker for the current location
            var positionMarker = new google.maps.Marker({
                map: map,
                position: currentPosition,
                icon: 'http://maps.google.com/mapfiles/ms/micons/green.png'
            });
            
                        
            // Keep track of the map boundary that holds all markers
            var mapBoundary = new google.maps.LatLngBounds();
            mapBoundary.extend(currentPosition);
            
            // Set markers on the map from the @RemoteAction results
            var club;
            for(var i=0; i<clubs.length;i++){
                club = clubs[i];
                console.log(clubs[i]);
                setupMarker();
            }
            
            // Resize map to neatly fit all of the markers
            map.fitBounds(mapBoundary);

           function setupMarker(){ 
                var clubNavUrl;
                
                // Determine if we are in Salesforce1 and set navigation link appropriately
                try{
                    if(sforce.one){
                        clubNavUrl = 
                            'javascript:sforce.one.navigateToSObject(\'' + club.Id + '\')';
                    }
                } catch(err) {
                    console.log(err);
                    clubNavUrl = '\\' + club.Id;
                }
                
                var clubDetails = 
                    '<a href="' + clubNavUrl + '">' + 
                    club.Name + '</a><br/>' + 
                    club.Street_Address__c + '<br/>' + 
                    club.City_Address__c + '<br/>' + 
                    club.Phone__c;
               
               // Create the callout that will pop up on the marker     
               var infowindow = new google.maps.InfoWindow({ 
                   content: clubDetails
               });
               
               // Place the marker on the map   
               var marker = new google.maps.Marker({
                   map: map,
                   position: new google.maps.LatLng( 
                                   club.Address_Geo__Latitude__s, 
                                   club.Address_Geo__Longitude__s)
               });
               mapBoundary.extend(marker.getPosition());
               
               // Add the action to open up the panel when it's marker is clicked      
               google.maps.event.addListener(marker, 'click', function(){
                   infowindow.open(map, marker);
               });
           }
        }
        
        // Fire the initialize function when the window loads
        google.maps.event.addDomListener(window, 'load', initialize);
        
    </script>
    
    <!--  All content is rendered by the Google Maps code -->
    <!--  This minimal HTML justs provide a target for GMaps to write to -->
    <body style="font-family: Arial; border: 0 none;">
        <div id="map-canvas"></div>
    </body>
</apex:page>

Controller:

Global Class ShowNearByPlaces{
    @RemoteAction
    Global static List<Account> findNearby(String lat, String lon) {
        Decimal Latitude = Decimal.valueOf(lat);
        Decimal Longitude = Decimal.valueOf(lon);

        List<Account> accList = [Select Id,Name, BillingStreet, BillingCity, BillingState, BillingPostalCode,BillingCountry, BillingLatitude, BillingLongitude,Geo_Location__Longitude__s, Geo_Location__Latitude__s FROM Account WHERE DISTANCE(Geo_Location__c, GEOLOCATION(:Latitude, :Longitude), 'mi') < 10];

        return accList;
    }
}