Voiceflow has released a new feature called Instant Assistant that allows users to build custom voice assistants from scratch or integrate it into their existing workflow. The feature offers several benefits, including safe experimentation with large language models (LLMs), accelerated workflows, supercharged customer conversations, and reduced operating expenses. Users can choose from various LLM options, such as GPT-3, GPT-3.5, GPT-4, Claude, and Claude Instant. To get started, users can follow three steps to build an instant assistant from scratch or integrate it into their existing workflow using a knowledge base data source. The feature is available on Voiceflow's free-forever plan, making it accessible to businesses of all sizes.