GTmetrix for WordPress
GTmetrix will make the WordPress blog faster, efficient and impressive for the search engines for fast indexing and give a better experience with fast loading. This plugin keep tracking your WP site and create alerts for your site. You can choose your own alerts on daily, weekly or monthly basis.
W3 Total Cache
This is one of the best WordPress fast plugins that make your site faster. It will give you an easy to use web performance optimization while using caching system. This plugin is supportive for database, browser, minify, page and objects of your site. This is only plugin that provide you improved and faster WordPress blogging experience.
BJ Lazy Load
BJ Lazy Loud will give you a faster blogging experience by saving bandwidth and using jQuery for non-JS users. This image friendly plugin replace all post thumbnails, post images and gravaters. The user of this plugin can lazy load other imageries and iframes, by using a simple function.
With the use of this plugin, you will know that your WordPress site is using optimally CloudFlare platform. It will provide you correct IP Address information for better commenting and better protection from spammers.
P3 (Plugin Performance Profiler)
You can create a performance report for your site, it will measure the impact of your site loading time and it will decrease. If your site is loading slowly by using some of the plugins, it will make your site light and give the user faster browsing experience.