If you're looking for an app to transcribe WhatsApp voice messages, EchoFox is a good option. It offers fast transcriptions, summaries and support for more than 90 languages. The app is designed to be easy to use and offers a private environment with high-level encryption and transcription deletion after 24 hours. It also integrates with other messaging apps like Facebook Messenger, Instagram and Telegram.
Another good option is WhisperBot, which uses OpenAI technology to convert voice messages into text. It supports more than 57 languages, offers high accuracy and works directly within WhatsApp, requiring no extra apps. WhisperBot is private, using WhatsApp's end-to-end encryption and deleting transcriptions after 30 minutes.