cdnjs is a free distributed JS library delivery service.
Google Maps is a web mapping service. It offers satellite imagery, aerial photography, street maps, 360° interactive panoramic views of streets, real-time traffic conditions, and route planning for traveling by foot, car, bicycle and air, or public transportation.
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.
Modernizr is a JavaScript library that detects the features available in a user's browser.
Javascript forms validation script.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Reveal elements as they enter the viewport.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.