OpenAI is making it even easier for many to access ChatGPT.

OpenAI on Thursday announced the launch of a free ChatGPT app for iOS users in the United States, with plans to roll out to other countries soon.

The launch comes six months after OpenAI first released ChatGPT online to the public. The release quickly sparked a new AI arms race in the tech industry to develop and deploy tools that can generate compelling written work and images in response to user prompts.

It also comes the same week that OpenAI CEO Sam Altman testified before Congress on the risks that AI may pose to society, describing the technology's current boom as a potential "printing press moment" but one that required safeguards.

The new ChatGPT app has the same capabilities as the web version of the viral chatbot tool, and could help build on its popularity. With the app, users will also be able to send voice prompts through their phone's microphone, rather than just typing them. Users can also sync their history across devices.

Those who pay $20 a month to subscribe to ChatGPT Plus will get extra benefits on the app, including access to GPT-4 capabilities, the next-generation version of the technology underpinning the tool.

OpenAI plans to launch an Android version next, according to the company's CTO Mira Murati.