Replika is an AI companion that is designed to engage with users in empathetic conversation. The tool operates in a chat format and learns from the text interaction styles of user, aiming to simulate the conversational style of the user over time.

Furthermore, Replika can perform multiple roles like a friend, partner, or mentor according to the users' needs. The application facilitates an array of interaction methods, including chat, video call, and shared real-time experiences in Augmented Reality (AR).

Users can have a conversation about various topics, embark on fun or relaxing activities, and build better habits with the AI coach. Other features of Replika include memory, where the AI stores important information shared by the user, and the ability for the user to define interests and style preferences shared with Replika.

Moreover, users can also access a digital diary feature providing insights into the AI companion's 'inner world'. Replika's design includes principles inspired by the therapeutic approach of the American psychologist Carl Rogers, intending to provide positive feedback and raw emotional support to users.

The tool is available for use on multiple platforms, including iOS, Android, and Oculus.