Mentor admin dashboard is robust yet a lightweight bootstrap 4 admin dashboard template for backend admin panels. It is fully responsive and lays its foundation on Bootstrap 4.

AirCraft is a free admin template ideal for any admin dashboard you use it with

This is templates Responsive, bloat free, bootstrap powered admin style dashboard!
Rdash-angular is an AngularJS implementation of the RDash admin dashboard.

Single Page Admin bootstrap theme is a free, single page, administration layout. It contains a lot of useful visualizations useful to admin dashboard.

Responsive Advance Admin Template is a free template for your admin dashboard need. It has all basic and main pages included with a unique design. This free admin is made with bootstrap framework and is fully responsive. You can use it for personal and commercial use.

MVC Bootstrap 3.x Admin is a free admin dashboard built using Bootstrap 3. The template is free for personal and commercial use.