jQuery Tree plugin allows you to create tree structure using Bootstrap or Material Design styles. Free open source plugin distributed under MIT License.
Pit-scheduler is a jQuery plugin that lets you manage tasks through a complete interface. It's compatible with Bootstrap and available under the MIT license (free to use).
Muuri creates responsive, sortable, filterable and draggable grid layouts with lots of features in one library. Comparing to what's out there Muuri is a combination of Packery, Masonry, Isotope and jQuery UI sortable.
Notyf is under MIT licence.