DeepSeek AI Assistant is an open-source app developed by the Chinese startup DeepSeek, powered by their advanced R1 model. It offers three main features: answering questions, internet search mode, and "DeepThink" for step-by-step reasoning. The app has quickly gained popularity, becoming the top downloaded app in Apple's US App Store, and poses competition to major AI services. However, it censors sensitive topics in line with China's internet policies.