<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Our app title</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width">
    <!-- OpenLayers CSS -->
    <link rel="stylesheet" href="http://openlayers.org/en/v3.0.0/css/ol.css" type="text/css">

    <!-- Our app style -->
    <style>
      .map {
        vw: 100vw;
        vh: 100vh;
      };
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <!-- Our app HTML tags here -->
    <!-- OpenLayers JS-->
    <script src="http://openlayers.org/en/v3.0.0/build/ol.js" type="text/javascript"></script>
    <!-- Our app code -->
    <script>
var map = new ol.Map({
  target: 'map',
  layers: [
    new ol.layer.Tile({
      source: new ol.source.MapQuest({layer: 'sat'})
    })
  ],
  view: new ol.View({
    center: ol.proj.transform([23.7, 61.5], 'EPSG:4326', 'EPSG:3857'),
    zoom: 11
  })
});
    </script>

  </body>
</html>

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Our app title</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width">
    <!-- OpenLayers CSS -->
    <link rel="stylesheet" href="http://openlayers.org/en/v3.0.0/css/ol.css" type="text/css">

    <!-- Our app style -->
    <style>
      .map {
        vw: 100vw;
        vh: 100vh;
      };
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <!-- Our app HTML tags here -->
    <!-- OpenLayers JS-->
    <script src="http://openlayers.org/en/v3.0.0/build/ol.js" type="text/javascript"></script>
    <!-- Our app code -->
    <script>
var map = new ol.Map({
  target: 'map',
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM()
    })
  ],
  view: new ol.View({
    center: ol.proj.transform([23.7, 61.5], 'EPSG:4326', 'EPSG:3857'),
    zoom: 11
  })
});
    </script>

  </body>
</html>

Switch base layer to OSM
Switch base layer to OSM
