Conclusion:

FlatBox has a global rank of 549 and an overall pagespeed score of 89.
FlatBox uses 11 resources in total, which is 119 kB of data.

This theme is faster than 78.77% of other themes we have tested.

Description by publisher:

A beautifully FlatBox with 8 flat design color schemes. It aslo a responsive theme, you can use in mobile, ipad or desktop. You can upload your own logo & favicon, customizable colors and background, 8 flat design theme color scheme, 3 different theme layout options, customize archive Posts (hide feature image, hide metadata and show post excerpt), single Post(hide feature image, hide related post and hide author box), and google fonts select for Customize: Body, Site Title, Heading, Sub-Heading. live the theme demo at http://www.wpbars.com/go/flatbox.