Building a language learning app where learners need speaking practice but human tutors at scale are too expensive and basic chatbots don't correct pronunciation?
Your language course content is ready but the off-the-shelf platforms take a large revenue cut and don't give you control over the learning path or learner data?
Language Learning App Development
Custom language learning apps for ed-startups, language schools, and publishers -- built with spaced repetition, speech recognition, AI conversation practice, and gamification that keeps learners coming back every day.
100+ products shipped since 2019. We've built audio-driven learning products for music education, and we apply the same approach to language apps -- audio feedback, visual scoring, and structured lesson delivery.
Spaced repetition vocabulary system and speech recognition with pronunciation scoring
AI conversation practice powered by LLMs with grammar correction and vocabulary suggestion
Gamification -- streaks, XP, leaderboards, and badges -- built to drive daily practice
Live tutor booking, video sessions, and progress analytics by skill and CEFR level
RaftLabs builds custom language learning apps for ed-startups, language schools, and publishers. Language learning app development covers spaced repetition vocabulary systems, speech recognition and pronunciation scoring, AI conversation practice, structured lesson delivery by CEFR level, gamification mechanics, live tutor booking and video sessions, and progress analytics. Custom builds are appropriate when off-the-shelf platforms take a large revenue cut, restrict your learning path design, or don't give you access to learner data. Most language learning app projects deliver in 12--16 weeks at a fixed cost with full source code ownership.
100+Products shipped since 2019
·SpeechRecognition built-in
·FixedCost delivery
·12-16Week delivery
Generic language platforms were built for everyone. That means they were built for no one in particular.
Duolingo spent years and hundreds of millions of dollars building their learning engine. A language school, a publisher, or an ed-startup cannot replicate that by buying a white-label SaaS platform that takes 30% of your revenue and locks your learner data behind their dashboard. The platforms that exist are opinionated about lesson structure, exercise types, and monetisation in ways that may not match your content or your audience.
Custom language learning app development builds the product around your curriculum, your target languages, and your learner journey -- whether that is structured CEFR-aligned lessons, free-form AI conversation practice, a live tutor marketplace, or a combination of all three.
What we build
Spaced repetition vocabulary system
SM-2 or similar scheduling algorithm for vocabulary and phrase decks, so each card comes back at the interval that best reinforces memory before it fades. Audio pronunciation by native speaker for every vocabulary item. Image association for visual learners. Exercise types include cloze deletion, multiple choice, and translation prompts. Performance-based card scheduling adjusts intervals based on how well the learner recalls each item. Decks are organised by topic and CEFR level so learners always know where they stand.
Speech recognition and pronunciation scoring
Integration with Google Speech-to-Text or Azure Cognitive Services for real-time speech analysis. Phoneme-level pronunciation accuracy scoring tells learners exactly which sounds need work -- not just pass or fail. Visual feedback highlights problem sounds against the target phoneme. Record and compare plays the learner's recording alongside a native speaker reference. Progressive pronunciation exercises move from isolated sounds to full sentences as accuracy improves.
AI conversation practice
LLM-powered conversation partner for free-form speaking and writing practice. Grammar error correction with plain-language explanation, not just a red underline. Vocabulary suggestion in context when the learner reaches for a word they haven't learned yet. Topic-based conversation scenarios -- travel, business, daily life -- give structure to open-ended practice. Adjustable difficulty and response speed so beginners aren't overwhelmed and advanced learners aren't bored.
Structured lesson delivery
Lesson sequencing by grammar concept and CEFR level so learners build on what they know before tackling new material. Mixed exercise types within a single lesson -- reading, listening, writing, and speaking -- to practise all four skills in context. Audio and video content with transcripts for listening comprehension exercises. Grammar explanation with worked examples, not abstract rules. Progress gating keeps learners from skipping prerequisites and arriving at advanced lessons without the foundation.
Gamification and engagement mechanics
Daily streak tracking with streak freeze mechanics so one missed day doesn't end a month-long habit. XP and level progression tied to lesson completion and exercise accuracy. Leaderboards scoped to friend groups and global rankings so learners compete against people they know and people they aspire to beat. Achievement badges for milestones -- first 100 words, 30-day streak, first conversation completed. Push notifications for daily practice reminders. Streak recovery offers reduce churn after a missed day rather than letting the learner drift.
Live tutor booking and sessions
Marketplace of language tutors with filtering by language, subject specialism, and availability. Calendar-based booking with timezone handling so learners in Tokyo and tutors in Madrid don't end up in the wrong meeting. Video session delivery via WebRTC or a third-party video provider. Session notes and vocabulary recap saved to the learner profile so the practice from each session feeds back into the spaced repetition deck. Rating and review system for tutors so quality rises to the top.
Frequently asked questions
We integrate with Google Speech-to-Text or Azure Cognitive Services for the speech-to-text layer, then apply phoneme alignment to compare what the learner said against what they were supposed to say at the sound level. This produces a per-phoneme accuracy score rather than a binary correct/incorrect result. The front end renders that score visually -- typically a waveform or phoneme grid highlighting problem sounds -- and plays back the learner's recording alongside a native speaker reference for comparison. The speech pipeline runs in real time on the device or via a low-latency API call, so feedback appears within a second of the learner finishing a recording.
The core architecture -- spaced repetition, lesson sequencing, gamification, and analytics -- is language-agnostic. The speech recognition and pronunciation scoring depend on what the underlying speech API supports. Google Speech-to-Text covers over 125 languages and dialects; Azure Cognitive Services covers a similar range. Native speaker audio for vocabulary items needs to be recorded or licensed for each target language you support. Script rendering for right-to-left languages (Arabic, Hebrew) and logographic scripts (Chinese, Japanese) requires specific front-end handling, which we build in from the start if your target language list includes them.
Gamification in language apps only works if the mechanics are tied to real learning actions rather than arbitrary point accumulation. We design streak tracking around daily practice sessions with a minimum completion threshold -- the learner has to finish a lesson or hit a vocabulary review target, not just open the app. Streak freezes are rationed so they protect streaks without replacing actual practice. XP is earned on accuracy and difficulty, not just volume, so grinding easy reviews doesn't substitute for real progress. Leaderboards reset weekly so new learners can compete without being permanently outranked by day-one users. We tune the notification cadence based on your learner cohort's drop-off patterns during early testing.
A focused language learning app -- spaced repetition vocabulary, structured lessons, basic gamification (streaks, XP, badges), and a progress dashboard -- typically runs $30,000--$70,000. Adding speech recognition and pronunciation scoring, an AI conversation practice module, or a live tutor marketplace each adds meaningful scope and cost. A full-featured product with all of these capabilities, multi-language support, and subscription billing typically runs $80,000--$180,000. Cost depends on the number of target languages, speech API integration complexity, tutor marketplace scope, and mobile platform requirements (iOS, Android, or both). We scope every project before pricing it.
Talk to us about your language learning app.
Tell us your target languages, your content, your learner audience, and what the existing platforms can't give you. We'll scope the right product and give you a fixed cost.
