Free bling admin theme is fully responsive for bootstrap lovers, based on bootstrap - under MIT license. do whatever you want to do :)
Bootcatch is an open source library of free Bootstrap templates and themes. All of the free templates and themes on Bootcatch are released under the MIT license, which means you can use them for any purpose, even for commercial projects.
After downloading, you can do whatever you want to do, like you can do changes in CSS and HTML files and make awesome templates as you want. hope this will help you.
git clone https://github.com/ajaymarathe/bling-admin-theme.git
Thanks to Creative Tim - this theme is based on Material Dashboard - v2.1.0.