Apollo AI is a versatile utility tool designed for iPhone users, allowing seamless interaction with various language models. This application enables users to chat with private and local AIs, connect to open source models, and even utilize their own locally-hosted large language models (LLMs). With features like experimental local model support, Apollo offers a secure and private way to run smaller LLMs directly on the device, ensuring user data remains confidential.

Additionally, Apollo supports OpenRouter, allowing users to integrate an OpenRouter API key for access to a wide array of models available online. By creating an account with OpenRouter, users can engage with both open source models, such as Meta Llama 3, and proprietary options like OpenAI's ChatGPT-4. The application also facilitates custom backend support, letting users run their own LLMs on personal computers and connect them to Apollo, providing a personalized AI experience for families.