Lity is a ultra-lightweight, accessible and responsive lightbox plugin which supports images, iframes and inline content out of the box. It requires jQuery or Zepto
jcSlider is a jQuery plugin to create responsive slider with CSS animations.
SmartPhoto.js is an easy to use responsive image viewer especially for mobile devices.
Restive.js is a designer-friendly jQuery toolkit for building mobile-friendly websites.
Using a combination of smart device detection, advanced breakpoints management, and timely CSS class additions, restive.js will make it easier for you to build mobile-friendly and/or responsive Web pages.
GridTab is a lightweight jQuery plugin to create grid based responsive tabs.
Notyf is under MIT licence.
EasyFader is an ultralight fading slideshow plugin for responsive layouts by using jQuery.
A tutorial about creating Responsive Flip Pricing Table to view month or year price by using jQuery and CSS.
Unite Gallery is a responsive jQuery image and video gallery plugin. This gallery is very powerfull, fast and has the most of nowdays must have features like responsiveness, touch enabled and even zoom feature, it's unique effect.
A tutorial about creating responsive table in Material Design concept. You can use this table in Bootstrap projects, this will override basic Bootstrap style.