Add ESRB ratings icons to steam store. I used the "Control Freak" chrome extension to add the following script. Add a script for http://http://store.steampowered.com/ pasting the text below Add Jquery 2.0.2 (http://ajax.googleapis.com/ajax/libs/jquery/2.0.2/jquery.min.js) in the Libs section. Reload http://store.steampowered.com/

overlay_ESRB_in_Steam.js

$(".tab_desc h4").each(function(e){ 
  var self = $(this);
  var game = $(this).text().split(" ").join("+");
  
//  var data = {
//    titleOrPublisher: self.text(),
//    isIncluding: false,
//    rating: "",
//    ratingsCriteria: "",
//    platforms: "",
//    platformsCriteria: "--All Platforms--",
//    searchVersion: "compact",
//    content: "",
//    searchType: "title",
//    contentCriteria: "",
//    newSearch: {x: 802, y: 400}    
//  };
  var data = "titleOrPublisher="+game+"&isIncluding=false&rating=&ratingsCriteria=&platforms=Linux%2CMacintosh%2CPC+DVD%2CPC+DVD-ROM%2CWindows+CE%2CWindows+PC%2CWindows+8+App&platformsCriteria=Linux%2CMacintosh%2CPC+DVD%2CPC+DVD-ROM%2CWindows+CE%2CWindows+PC%2CWindows+8+App&searchVersion=compact&content=&searchType=title&contentCriteria=&newSearch.x=802&newSearch.y=400";
  window.console&&console.log("search for: "+game);
$.post( 
  "http://www.esrb.org/ratings/search.jsp", 
  data, 
  function(data){
    var img = $(data).find(".results .ratingiconwidth img").first();
    var game_title = img.parents("tbody").first().find("strong").first().text();
    var text = img.parents("tbody").first().find("strong").parent().last().text();
    img.attr("src", img.attr("src").replace("..", "http://www.esrb.org"));
    self.after(img);
    self.after($("<span>"+game_title+"</br>"+text+"</span>"));
  }).fail(
  function(data){self.after($("<p>Can't find it</p>"));});

});

version2.js

$(".tab_desc h4").each(function(e){ 
  var self = $(this);
  var game = $(this).text().split(" ").join("+");
  
  var data = {
    titleOrPublisher: self.text(),
    isIncluding: false,
//    rating: "",
//    ratingsCriteria: "",
//    platforms: "",
//    platformsCriteria: "--All Platforms--",
    searchVersion: "compact",
//    content: "",
    searchType: "title",
//    contentCriteria: "",
//    newSearch: {x: 802, y: 400}    
  };
//  var data = "titleOrPublisher="+game+"&isIncluding=false&rating=&ratingsCriteria=&platforms=Linux%2CMacintosh%2CPC+DVD%2CPC+DVD-ROM%2CWindows+CE%2CWindows+PC%2CWindows+8+App&platformsCriteria=Linux%2CMacintosh%2CPC+DVD%2CPC+DVD-ROM%2CWindows+CE%2CWindows+PC%2CWindows+8+App&searchVersion=compact&content=&searchType=title&contentCriteria=&newSearch.x=802&newSearch.y=400";
  window.console&&console.log("search for: "+game);
$.post( 
  "http://www.esrb.org/ratings/search.jsp", 
  data, 
  function(data){
    var img = $(data).find(".results .ratingiconwidth img").first();
    var game_title = img.parents("tbody").first().find("strong").first().text();
    var text = img.parents("tbody").first().find("strong").parent().last().text();
    img.attr("src", img.attr("src").replace("..", "http://www.esrb.org"));
    self.after(img);
    self.after($("<span>"+game_title+"</br>"+text+"</span>"));
  }).fail(
  function(data){self.after($("<p>Can't find it</p>"));});

});