01
It has to answer instantly
Wait two seconds for a reply and the learner stops talking. The teacher has to answer like a person on a call.
Client
Jan van der Aa, CEO
Industry
EdTech & Learning
Surfaces
iOS · Android · Web · Embed
Scope
Voice AI · Product engineering
Case study · Voice-first AI
Learners Speak with AI Clones of the Teachers They Already Follow.
Teacher AI is a speaking-practice platform Kodexo Labs built for its client: voice-cloned AI teachers, real-time correction, and one shared engine serving both a consumer app and free embeds inside language schools' own courses.
10,000+
Active students
500K+
Conversations completed
2M+
Words practiced
01 · Overview
A Speaking Coach That Answers Back, at 6am, in Your Language.
Teacher AI is built for intermediate learners (A2+) who can read a language but freeze when someone talks back. Instead of drills, they hold a real conversation with an AI teacher cloned from a YouTube instructor they already watch, same voice, same accent, same teaching manner.
Conversation, correction, and voice run as one engine behind every surface, and ship through two channels: a subscription app for individual learners, and a free embed that drops a guided speaking exercise into a language school's own course platform.
02 · The Problem
You Know the Words. You Still Freeze When Someone Talks to You.
A human tutor fixes that, but tutoring never scaled. It costs money, needs scheduling, and nobody wants to waste someone's hour on their own mistakes. Seven things had to be true for software to take that job.
02
A wrong correction is worse than none
Correct something that was already right and the learner stops trusting every correction after it.
03
The teacher has to sound like the teacher
Learners come for a face they follow. The cloned voice must match, every session, in every language.
04
Schools will not install software
Course creators have no engineers. It had to be one snippet pasted into a lesson, with no login and no app.
05
The wrong learner buys it
This is speaking practice, not a beginner course. The product has to say who it is for before anyone pays.
06
Phones lose signal
Practice happens on the commute. A dropped call cannot cost the conversation or the progress.
07
Two audiences, two rush hours
One learner practises daily; a class launch sends hundreds at once. Neither can slow the other down.
01
It has to answer instantly
Wait two seconds for a reply and the learner stops talking. The teacher has to answer like a person on a call.
02
A wrong correction is worse than none
Correct something that was already right and the learner stops trusting every correction after it.
03
The teacher has to sound like the teacher
Learners come for a face they follow. The cloned voice must match, every session, in every language.
04
Schools will not install software
Course creators have no engineers. It had to be one snippet pasted into a lesson, with no login and no app.
Client review · Clutch-verified
“The offered impressive value for money.”
Users are buying and liking the client's product. The team regularly delivered items on time and communicated via virtual meetings, emails, and messages. They offered a remarkable value for money.
4.0
out of 5 on Clutch
Custom software development · June 2023 to Feb 2024
Quality
4.0
Schedule
4.0
Cost
4.0
Willing to Refer
4.0
Verified review
03 · The Solution
Tap Once, Start Talking. Your Teacher Is Already Listening.
Four decisions carry the product: a streaming voice loop fast enough to feel like a call, correction the learner controls, teacher personas that stay in character, and a language switch that never resets progress. Eight more capabilities sit behind them.
Capability 01
A Voice Loop Tuned for Turn-Taking, Not Transcription
Speech streams to text as the learner talks, end-of-turn is detected from natural pauses rather than a stop button, and the teacher's cloned voice streams back while the rest of the reply is still generating. Drop the connection and the session is already saved.
Pause-based end-of-turnAccent-tolerant STTText fallback on degrade
Capability 02
Correction the Learner Sets the Volume On
Mistakes are rephrased softly in the flow of conversation, the way a friend corrects you. When the learner wants the full reason, one button breaks down what was wrong and how to say it next time. Instruction language, correction style and frequency, formality, and speaking pace are all theirs to set.
Soft
inline rephrase, conversation never stops
Hard
on-demand grammar breakdown per message
Tap
in-context translation without leaving the chat
Capability 03
Teachers Who Stay in Character
Every persona carries a cloned voice, an accent, a difficulty calibration, and a conversational manner. Learners browse the roster the way they'd pick a tutor, pronunciation accuracy, whether the teacher can slow down, whether they can explain in the learner's own language, then read a full profile before committing.
Voice cloned from sample audioPer-teacher difficultySwitch mid-session
Capability 04
Pick One Language, Get All of Them
Subscribing unlocks every supported language at once. There is no per-language paywall and no second purchase. Switching re-scopes the teacher roster, vocabulary tracking, and translation base language, and leaves the learner's counts in each language intact.
30+
consumer languages
60+
on the schools channel
Everything Else the Learner Gets
The rest of the specified feature set, all running on the same conversation engine.
Type instead of talk
Same teacher, same corrections, in text. Built for a quiet train or a bad connection.
Say it after me
Word and sentence scoring against a native recording, side by side, so you hear where you drifted.
Tap any word
An in-context translation appears without leaving the conversation.
Words you actually used
New vocabulary is captured from your own conversations into a saved list and flashcards.
Order coffee, pass an interview
Scenarios from restaurants and airports to job interviews and business meetings, each with its own register.
Harder only when you are ready
Difficulty and vocabulary track what you have demonstrated, not the level you claimed at signup.
A reason to come back tomorrow
Daily goals, streaks, XP, and badges, with reminders that stop when you have practised.
Proof you are improving
Minutes spoken, words learned, fluency and accuracy scores, weekly and monthly, plus every past chat to resume.
Type instead of talk
Same teacher, same corrections, in text. Built for a quiet train or a bad connection.
Say it after me
Word and sentence scoring against a native recording, side by side, so you hear where you drifted.
Tap any word
An in-context translation appears without leaving the conversation.
Words you actually used
New vocabulary is captured from your own conversations into a saved list and flashcards.
Order coffee, pass an interview
Scenarios from restaurants and airports to job interviews and business meetings, each with its own register.
Harder only when you are ready
Difficulty and vocabulary track what you have demonstrated, not the level you claimed at signup.
A reason to come back tomorrow
Daily goals, streaks, XP, and badges, with reminders that stop when you have practised.
Proof you are improving
Minutes spoken, words learned, fluency and accuracy scores, weekly and monthly, plus every past chat to resume.
On mobile
The Same Session, in a Pocket, on the Commute
iOS and Android share the web app's engine and state. A conversation started on a laptop continues on a phone with the same teacher, streak, and saved words.
Language picker
Words known and words remaining per language, so switching is a decision, not a reset.
Units by CEFR level
Scenario sets grouped A1 through C1. Each one opens into a scoped conversation.
In-session teacher sheet
Swap teacher or adjust preferences without leaving the conversation.
Teacher profile
Background, languages, and habits: enough personality to make small talk land.
Language picker
Words known and words remaining per language, so switching is a decision, not a reset.
Units by CEFR level
Scenario sets grouped A1 through C1. Each one opens into a scoped conversation.
In-session teacher sheet
Swap teacher or adjust preferences without leaving the conversation.
Teacher profile
Background, languages, and habits: enough personality to make small talk land.
04 · Architecture
Here Is What Happens When You Press the Button and Start Talking.
Read it top to bottom: where people open the app, the services that run the lesson, the voice technology that hears and speaks, and where everything is stored. A school's course page uses exactly the same engine as the app.
1
Where people open it
Phone apps
iPhone and Android
Website
Same lesson in the browser
A school's own lesson page
Practice built into the course, no sign-up
Phone apps
iPhone and Android
Website
Same lesson in the browser
A school's own lesson page
Practice built into the course, no sign-up
2
What runs the lesson
The conversation
Holds the thread, keeps your teacher in character, and picks the topic
The feedback
A gentle fix as you talk, a full explanation when you ask, translation on tap
Your progress
Words learned, minutes spoken, streaks, and scores over time
Signing in
Email, Google, or Apple, and you stay signed in
School courses
Turns a school's own lessons into speaking exercises
Plans and payments
Free trial, subscriptions, and restoring a purchase
Reminders
Practice nudges and account notices
The conversation
Holds the thread, keeps your teacher in character, and picks the topic
The feedback
A gentle fix as you talk, a full explanation when you ask, translation on tap
Your progress
Words learned, minutes spoken, streaks, and scores over time
Signing in
Email, Google, or Apple, and you stay signed in
School courses
Turns a school's own lessons into speaking exercises
Plans and payments
Free trial, subscriptions, and restoring a purchase
Reminders
Practice nudges and account notices
3
How it hears and speaks
Listens
Turns your speech into words, accents and pauses included
Thinks
Writes what the teacher says next, and notices mistakes
Speaks
Replies in your teacher's own cloned voice
Listens
Turns your speech into words, accents and pauses included
Thinks
Writes what the teacher says next, and notices mistakes
Speaks
Replies in your teacher's own cloned voice
4
What is kept
Your account and progress
Profile, plan, streaks, and scores
Your conversations and words
Past chats and saved vocabulary
School course material
Stored on its own, never mixed with personal chats
Your account and progress
Profile, plan, streaks, and scores
Your conversations and words
Past chats and saved vocabulary
School course material
Stored on its own, never mixed with personal chats
What happens in the second after you speak
You speakIt hears the wordsRemembers the threadWrites the replySlips in a correctionSpeaks in your teacher's voiceYou hear it
Your transcript, new words, and progress are saved along the way, so losing signal never costs you the conversation.
Distribution
Language Schools Hand Us Their Students.
Nobody installs anything. A school's own lesson page gains speaking practice, and the students who want more of it become subscribers.
01
A School Applies
It sends a link to its course and a line on what it teaches. That is the whole ask.
02
We Build the Exercises
Every module is read and gets one speaking exercise of its own, spoken in that school's instructor voice.
03
They Paste One Snippet
A single line of code per lesson. It works on Teachable, Circle, Thinkific, Kajabi, and anything that takes an embed.
Live in 5 to 7 business days
Free
The School Pays Nothing
Every student gets one complete exercise per module, with real corrections and no sign-up. After it ends, a quiet prompt offers unlimited practice.
Revenue comes from the students who upgrade.
School plan
The School Pays Per Student
Unlimited practice for everyone, every teacher and language, saved progress and monthly leaderboards, plus an analytics dashboard for the school.
No upsell is ever shown to its students.
Trust
Speaking Out Loud Is Personal.
People say more when they know where the recording goes, so these three rules were built in from the start rather than bolted on.
Your Voice Stays Yours
Audio and transcripts travel encrypted, and are never sold or passed to anyone beyond the service that turns speech into words.
Close the Account and It Is Gone
Ask for deletion and the profile, the recordings, and the transcripts all go with it.
One School Never Sees Another
Course material is stored on its own, and no guest session can reach another student's work.
Your Voice Stays Yours
Audio and transcripts travel encrypted, and are never sold or passed to anyone beyond the service that turns speech into words.
Close the Account and It Is Gone
Ask for deletion and the profile, the recordings, and the transcripts all go with it.
One School Never Sees Another
Course material is stored on its own, and no guest session can reach another student's work.
05 · Outcomes
People Stopped Studying and Started Speaking.
Half a million conversations is the number that matters. It means learners came back, opened their mouths, and kept going.
Reached
01
10,000+
Active Students
who show up to speak, not to swipe flashcards
Sustained
02
500,000+
Conversations Completed
the number that proves they came back
Activated
03
2M+
Words Practiced Aloud
said out loud, not read off a screen
Rated
04
4.3
Stars on the App Store
across 500+ ratings
Scaled to
05
30+
Languages for Learners
and 60+ on the schools channel
Onboards in
06
5 to 7
Business Days
from a school applying to live lessons
Reached
01
10,000+
Active Students
who show up to speak, not to swipe flashcards
Sustained
02
500,000+
Conversations Completed
the number that proves they came back
Activated
03
2M+
Words Practiced Aloud
said out loud, not read off a screen
Rated
04
4.3
Stars on the App Store
across 500+ ratings
Scaled to
05
30+
Languages for Learners
and 60+ on the schools channel
Onboards in
06
5 to 7
Business Days
from a school applying to live lessons
FAQ
What Teams Ask Us Before Building Something Like This.
The questions that come up in almost every first call about a voice-first learning product.
Thinking About a Voice-First Product of Your Own?
Twenty minutes with a senior engineer who has shipped one. Bring the idea, leave with a straight answer on scope, latency, and cost.
51
Products Shipped
Across 25+ industries
94%
Client Retention
Across every engagement
Top
Rated on Clutch
Elite AI Firm designation
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