To develop an Android app, learning Java is essential. Recommended resources for learning Java include processing.org for hands-on experience with the Processing IDE, and tutorials from sites like Tutorialspoint, which provides foundational knowledge but lacks challenges. For beginners without prior programming experience, "Head First Java" is suggested. After grasping the basics, it's crucial to study algorithms and design patterns, as these are vital for Android development. The complexity of Android requires a comprehensive understanding of various concepts. Additional resources for practice include Codingbat for problem-solving and Treehouse for structured Android learning, praised for its user-friendly interface. YouTube is also highlighted as a valuable tool for supplementary learning. Multiple sources are encouraged for a well-rounded education.