Marketing Course by Apps.21 is a free Android application that provides basic knowledge in business marketing and management. The app is designed for all individuals who wish to learn about different areas of marketing and market research. The app is available in multiple languages, and users can select their preferred language using the "Select Language" button.

The app is user-friendly and offers a comprehensive learning experience to its users. The course is divided into different sections, each containing detailed information about various marketing concepts. The app covers a wide range of topics, including market research, consumer behavior, target market, product development, pricing strategies, promotion, advertising, and sales. The course is easy to follow, and the content is presented in a clear and concise manner, making it easy for users to understand and apply the concepts in real-life scenarios.