yii2-adminlte is a package for yii framework 2 that consists a very popular backend template AdminLTE (based on bootstrap 3). It is the best free solution for administrate zone.
This package includes theme requirements and base widgets for comfortable using in your web applications.
The preferred way to install this extension is through composer.
Either run
composer require --prefer-dist factorenergia/yii2-adminlte "*"
or add the following to the require section of your composer.json
"factorenergia/yii2-adminlte": "*"You may see a demo site here.