Speak. Then understand.
Confirm your transcript. See the marked words and the grammar rule behind the correction.
RedpenAn AI English speaking tutor for iPhone.
Your words.
A clearer sentence.
Say a sentence. See the mistakes it finds.
Understand the rule. Say it again.
Available now
Coming soon$4.99/week · 3-day free trial for eligible users.
AI can make mistakes.
What is Redpen?
Redpen is an AI English speaking tutor app for iPhone. You say a sentence, and Redpen marks the mistakes it finds in red, names the grammar rule and explains it in Spanish, Vietnamese or English, then lets you say the corrected sentence.
A sentence.
A rule. Another try.
Speak and confirm. Understand the rule. Repeat the correction. Start with something you actually want to say.
Say the correction.
Practise the corrected sentence aloud. The drill checks the words you repeat, not pronunciation.
Keep the rule.
Your Notebook groups saved mistakes by rule, ready for another practice round.
Explanations in Spanish and Vietnamese.
English explanations for everyone else.
Is Redpen right for you?
| You want | Redpen |
|---|---|
| Your spoken sentences marked for grammar mistakes | Yes. The mistakes it finds are marked in red, with the rule named. |
| The explanation in Spanish | Yes. Explanations are in Spanish and Vietnamese, and English for other languages. |
| To say the corrected sentence aloud | Yes. The drill checks that you repeat the corrected words. |
| A list of the mistakes you repeat | Yes. The Notebook groups saved mistakes by grammar rule. |
| A pronunciation score | No. Redpen does not assess pronunciation. |
| A free app | No. Eligible users get a 3-day free trial, then $4.99 per week. |
| A human teacher | No. Redpen is an AI tutor app, and AI can make mistakes. |
| An Android app | Not yet. Google Play is coming soon. |
Your practice.
$4.99 a week.
Start with 3 days free.
For eligible users. Then $4.99/week.
Corrections, rule explanations, sentence drills and your Notebook, in one subscription.
Apple bills your subscription. Payment is charged to your Apple Account at confirmation or when your trial ends. It renews automatically unless cancelled at least 24 hours before the current period ends.
Manage or cancel in Apple Settings. Deleting the app or your account does not cancel billing. Local price and trial eligibility appear in the app.
Manage an Apple subscription ↗A few clear answers.
Is Redpen an AI tutor?
Yes. Redpen is an AI English speaking tutor app, not a human teacher. It marks possible grammar mistakes and explains the rule. AI can make mistakes.
How does Redpen correct my English?
You say a sentence and confirm the transcript. Redpen marks the mistakes it finds in red, names the grammar rule and explains it. Then you say the corrected sentence in a short drill, and your Notebook keeps the mistake for another round.
Does Redpen explain mistakes in Spanish?
Yes. Grammar explanations are available in Spanish and Vietnamese. Other native languages receive English explanations.
Is Redpen free?
No. Redpen is a subscription. Eligible users get a 3-day free trial, then pay $4.99 per week. Local price and eligibility appear in the app.
Who is it for?
Adult English learners whose first language is Spanish, Brazilian Portuguese, Japanese, Korean, Vietnamese or Turkish. Grammar explanations are available in Spanish and Vietnamese. Other native languages receive English explanations. English is available to everyone.
What happens to my voice and words?
Audio stays on your phone. Only the transcript you review and confirm is sent for correction, after your consent. Unsaved transcripts expire after 30 days. Saved Notebook entries stay until you delete them. You can delete your account anytime.
Does it assess pronunciation?
The drill checks whether you repeat the corrected words. It does not assess pronunciation.
How do the trial and subscription work?
Eligible users get a 3-day free trial, then pay $4.99 per week. Apple bills the subscription, which renews automatically unless cancelled at least 24 hours before the current period ends. Manage or cancel in Apple Settings. Deleting the app or your account does not cancel the subscription. Local price and eligibility appear in the app.
Can I download it now?
Redpen is available on the App Store. Google Play is coming soon. Use the store badges above for available downloads.