Google sheets interface to the World Bank API. Paste this code into the Google Sheets script editor to add a custom function.

WBAPI.gs

/**
 * Fetches data from the World Bank API
 *
 * @param {string} indicator The indicator code
 * @param {string} country The 2- or 3-character ISO country code
 * @param {number} year The optional year. If omitted, fetch most recent available
 * @return The data value.
 * @customfunction
 */
function WBAPI(indicator, country, year) {

  var url = 'http://api.worldbank.org/v2/en/country/' + country + '/indicator/' + indicator + '?'
  
  if( year == undefined ) {
    url += 'MRV=1'
  }
  else {
    url += 'date=' + year
  }
  
  url += '&format=json'
  
  var response = UrlFetchApp.fetch(url);
  
  var json = response.getContentText()
  var data = JSON.parse(json)
  
  if( data.length < 2 ) {
    // whoops, there's an error. Likely an invalid function parameter
    return data[0].message[0].key
  }
  
  return data[1][0].value
}