My Simple Theme
Starting out as a mobile-friendly theme, the code has been under an overhaul recently to turn the theme into mobile first. What this means is that there will be less code required to ensure your site works great on mobile devices and desktops as well. This change also allows for more dynamic displaying of sidebars.
My Simple Space
Stop guessing the space your site is using. My Simple Space shows you the basics: PHP version, memory (total and used), database size, as well as the total site size. There is also a basic breakdown of the wp-content folder (plugins, themes, uploads), as well as the wp-admin and wp-includes folders.
Simple Site Verify
Plugin which provides a simple site verification method with Bing, Google Webmaster Tools, Google Analytics, Pinterest, and Yandex.