Customizr is a versatile and easy to customize fully responsive professional WordPress theme. The developers claim that this theme is designed with visitor engagement in mind and allows anyone to create a beautiful, fast and mobile friendly website, compatible with all browsers and devices.
Customizing this theme is very simple and it works well with major WordPress plugins like WooCommerce, bbPress, Jetpack and many others. A Pro version is also available.
Full post : https://www.sitepoint.com/9-of-the-most-popular-free-wordpress-themes/