ImportJSON.gs

/**
* Imports JSON data to your spreadsheet Ex: IMPORTJSON("http://myapisite.com","city/population")
* @param url URL of your JSON data as string
* @param xpath simplified xpath as string
* @customfunction
*/
function IMPORTJSON(url,xpath){
  try{
    // /rates/EUR
    var res = UrlFetchApp.fetch(url);
    var content = res.getContentText();
    var json = JSON.parse(content);
    var patharray = xpath.split("/");
    //Logger.log(patharray);
    
    for(var i=0;i<patharray.length;i++){
      json = json[patharray[i]];
    }
    
    //Logger.log(typeof(json));
    if(typeof(json) === "undefined"){
      return "Node Not Available";
    } else if(typeof(json) === "object"){
      var tempArr = [];
      
      for(var obj in json){
        tempArr.push([obj,json[obj]]);
      }
      return tempArr;
    } else if(typeof(json) !== "object") {
      return json;
    }
  }
  catch(err){
      return "Error getting data";  
  }
}