Amazon Progress Tracker in Percentage

amazon_tracker_progress.js

// Amazon Progress Tracker in Percentage
// URL Pattern: 
//     amazon.com/progress-tracker/package/*
//     *.amazon.com/progress-tracker/package/*

var items = document.getElementsByClassName("js-milestone-bar");
var labels = document.getElementsByClassName("milestone-primaryMessage");

for (var i = 0; i < items.length; i++) 
{
    var percentage = parseInt(items[i].getAttribute("data-percentcomplete")) - 25;
    if (percentage > 0)
    {
        labels[i].innerHTML = labels[i].innerHTML + ' (' + Math.round(percentage / 0.75) + '%)';
        
        if (percentage < 50)
        {
            break;
        }
    }
}