Terrestrial alternatives

RTranslator is an (almost) open-source, free, and offline real-time translation app for Android. The app uses OpenAI's Whisper for speech recognition and Meta's NLLB for translation, it has 3 modes: a classic text translation mode; conversation mode: where you connect to one or more devices that have RTranslator to have a real-time translated conversation with other people (works best with Bluetooth headphones); walkieTalkie mode: where you can translate a conversation with a single device.