Augments the Google App Engine (GAE) instances overview page with the (instantaneous) average instance lifespan. Longer is better!

augmentGAEInstancesPage.js

// ==UserScript==
// @name       Augment GAE Instance List
// @version    0.1
// @namespace  http://www.dound.com/
// @description  augments instance page with average lifetime
// @match      https://appengine.google.com/instances*
// @require    https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js
// ==/UserScript==

window.setTimeout(function () {
    "use strict";
    var n = 0,
        sum = 0;
    $('#ae-instances-details-table tbody tr').each(function (i, e) {
        var agePieces = $(e).find('td')[4].innerHTML.trim().split(":");
        n += 1;
        sum += parseInt(agePieces[0], 10) * 3600 + parseInt(agePieces[1], 10) * 60 + parseInt(agePieces[2], 10);
    });
    $('#ae-instances-details-table caption').append("<span>Average Lifespan: " + (sum / n).toFixed(0) + " seconds</span>");
}, 1000);