undo Products
A speaking coach that runs on your computer.
Practice a new language out loud with on-device speech recognition and a private AI coach. No cloud, no accounts required — your voice and conversations never leave your machine.
What it does
Speak and get corrected
Say a sentence out loud and get a reply, a score from 1 to 10 and specific corrections, each with its reason. Or switch to plain conversation.
A coach with a personality
Samantha keeps one warm, consistent character and answers you out loud. Choose her tone, from a clear teacher to a playful friend.
Private, on your computer
By default, speech recognition, the AI coach and her voice all run on your own machine. Your recordings and conversations are not uploaded, and no account is needed.
Works offline
After a one-time model download it runs with the network off. Already have the model files? Import them from a folder instead of downloading.
She remembers you
Each session picks up from the last. Personal notes are kept only if you say yes, and you can confirm or delete every one in Settings.
Your level, your pace
Pick a level from A1 to C2, or let her match how you speak.
Also included
- Five languages
English, German, French, Italian and Spanish. Setup tells you honestly what your computer can hold and fetches the smallest coach that does it well.
- Corrects your writing
Open a PDF you wrote and she corrects it. Photos and scanned pages go through an optional reader, a separate download.
Photos and scans: Mac only - Saved words and phrases
Keep what you want to remember, add your own notes, and search and review them later.
- Voice commands
Register your own programs or shortcuts and start them by voice. By default you see a preview and confirm before anything runs, and the AI can only pick from your own list.
Not in the Mac App Store edition - Phone companion
Practise from your phone over your own Wi-Fi, paired with a one-time code. Off until you turn it on.
Commands from the phone: not in the Mac App Store edition - A floating companion
Hide the window mid-session and her orb stays on screen with you.
- Light, dark, your text size
Light, dark or follow the system, with adjustable text sizes.
Platforms
Windows 10 (1809) or later · x64 · .exe
The installer is not code-signed. If Windows says “Windows protected your PC”, choose More info, then Run anyway.
Not yet released.
Versions
Supported macOS builds (.dmg), newest first. Earlier releases are retired and prompt to update to the latest on launch.
- macOSv1.3.1Latest2026-10-01
- Her greeting is no longer lost. If macOS asks for the microphone while she is introducing herself, the screen waits for your answer instead of moving on without her.
- A voice you do not have no longer blocks setup. If your Mac lacks the voice the app asks for, she speaks with one that is already there and tells you so.
- A quieter start: the app no longer looks up a download size it already knows, so it opens the same way online or off.
- Clearer wording when a recording cannot be read.
- No longer hostedv1.3.02026-09-22
- Samantha remembers. The coach carries what you talked about from one session to the next, and keeps notes about you only after you say yes — see, correct or delete them in Settings ▸ Privacy.
- Bring a page. Drop in a PDF you wrote, or a photo of a handwritten or printed page with the optional reader (a separate 5.5 GB download), and she corrects your writing.
- Choose your language first: the app downloads the smallest coach that holds it well — 2.3 GB for English; 8.3 GB and 16 GB of memory for German, French, Italian and Spanish.
- Spoken replies in every language on a Mac with no extra voices, and voice input that needs nothing else installed.
- Coach voices now come only from the app's own copy — never from a third-party download — and are about 2.4 dB louder.
- Security: a voice turn that carries no audio can no longer reach the microphone.
- Now runs on macOS 14 or later.
- Many fixes: steadier corrections, a clearer setup and a smoother first run.
- No longer hostedv1.2.02026-08-03
- A floating companion that stays with you when you hide the window mid-session.
- A menu bar icon, and only ever one copy of the app running.
- Save your own commands and run them by voice, with a preview before anything executes.
- Your phone can now trigger those commands over your own network, behind a one-time code.
- Sign in with Apple, alongside Google.
- Now fully moved to undo.tech. macOS will ask once more for microphone and speech permission after this update — your settings, saved words and downloaded models are untouched.
- No longer hostedv1.1.12026-06-16
- Now connected to the new home at undo.tech.
- Faster spoken replies — the coach starts talking sooner.
- The phone companion now matches the desktop coach: shared memory across the conversation, your tuned personality, and the language you're practicing.
- Reliability improvements.
- Sign in with Google to keep your account across updates and devices.
- Messages from the developer, with optional star/text feedback.
- Updated Core Operating Protocols — please review them on first launch.
- More reliable startup and backend connection handling.
- Privacy: only basic, non-content usage analytics are shared — your conversations and audio never leave your device.
- Major release with Hybrid AI architecture.
- Implemented safety protocols and guidelines modal.
- No longer hostedv1.1.0