Meta AI is the consumer face of Meta's Llama model family, available across Facebook, Instagram, WhatsApp, and Messenger - as well as a standalone web interface. It's the AI assistant with perhaps the largest potential reach of any tool on this list, embedded in apps that already have billions of users. Meta AI can answer questions, generate images, help with planning, and engage in extended conversations. The image generation is powered by Meta's own Imagine tool. As a free product with no paid tier, its limitations are in depth and context length rather than cost. For casual users who want AI assistance without signing up for anything new, Meta AI is already in your pocket. For professionals with demanding tasks, dedicated tools serve better - but for quick queries in apps you already use, it's genuinely useful.