App builders are software tools that allow users to create mobile or web applications without needing extensive programming knowledge. They provide a user-friendly interface with drag-and-drop features, enabling individuals and businesses to design apps tailored to their needs. Popular app builders include platforms like Appy Pie, Bubble, and Adalo. These tools often come with pre-built templates and customizable components, making it easier for users to add functionalities such as databases, user authentication, and payment processing. App builders are ideal for entrepreneurs and small businesses looking to develop apps quickly and cost-effectively.