Building a messaging app like WhatsApp without coding requires using no-code tools, such as Bubble, which has made it easier for makers to start building software. The guide outlines the step-by-step process of creating a basic messaging app, including wireframing the user interface, setting up databases and data fields, and configuring workflows to send messages between users. By following this guide, users can create a functional messaging app without writing any code, and even customize it with additional features such as group chats and message reactions. With Bubble's paid plans starting at $25 per month, building a messaging app is more accessible than ever, without requiring significant development costs.