Pal Chat - AI Chat Client is a versatile AI chat application that operates on iOS devices. This lightweight yet potent tool is designed to utilize popular models like GPT-4 Turbo, GPT-4 Vision, DALL-E 3, Claude 3, Gemini, Perplexity AI among others and is also open to custom endpoints.

Its distinguishing features include capabilities to save multiple prompts and system messages, store conversation history on the device, edit queries, process images using GPT-4 Vision, generate visuals with DALL-E 3, and regenerate responses.

It also has full markdown, LaTeX, and syntax highlighting support. The text-to-speech ability allows users to heed to messages audibly, and one can easily switch between different models depending on the need.

A unique feature is the OpenRouter integration that facilitates easy access to various open-source/experimental LLM on the iPhone. Another important aspect is its focus on privacy, with the conversation history stored on the device itself.

Finally, the app necessitates an API Key to function, and Pal Chat does not bear responsibility for the content generated.