Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Responsive navigation plugin without library dependencies and with fast touch screen support.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.