Spaced repetition that adapts to your child
We use FSRS (Free Spaced Repetition Scheduler) — the same algorithm Anki users rate as the current state of the art. Every word your child sees gets scheduled for the moment they are most likely to forget it, and the schedule re-tunes itself based on their actual recall, not a generic "5/10/30 day" rule.
- New words introduced at a sustainable rate (default 7/day, parent adjustable)
- Failed cards re-enter a short learning cycle, not a permanent shame list
- Difficulty rating is implicit (response time + correctness), not a button kids dread
- No "review everything every day" — the algorithm decides
Tones taught explicitly, not as an afterthought
Mandarin tones are the #1 reason adult learners stall, because most apps treat them as a footnote. Bóyǎ teaches tone before meaning, with native-speaker audio on every card, pronunciation scoring on family-tier accounts, and a dedicated tone-pair drill in the daily quest.
- Native-speaker audio on every vocabulary card
- Tone-pair minimal pairs drill (mā vs. má vs. mǎ vs. mà) from day one
- Pronunciation scoring (family tier) gives concrete feedback, not just a green check
- Tone errors are surfaced in the parent dashboard as a separate weak category
Output before input
We don't make kids wait six months to speak. From week one, every session ends with the AI tutor (老师 Lin) asking a question and the child answering aloud. The tutor models the correct form rather than scolding, which research consistently shows produces better long-term retention than error correction.
- Weekly speaking time tracked in the parent dashboard
- Tutor mirrors the correct form rather than listing errors
- Output-first sequencing: hear, repeat, produce, recognize (in that order)
- No "you got it wrong" red flashes; mistakes are part of the loop
Curriculum: HSK-aligned, kid-readable
We follow the HSK standard (the Chinese government's standardized Mandarin proficiency framework) because it's the closest thing to a global Mandarin curriculum, and because it gives parents a concrete external benchmark. Free tier covers HSK 1–3 (~600 most-used words). Family tier adds HSK 4 (1,200 words).
- HSK 1: ~150 words — basic greetings, family, numbers
- HSK 2: ~150 more — daily life, time, weather, simple verbs
- HSK 3: ~300 more — school, hobbies, opinions, past/future
- HSK 4: ~600 more — abstract topics, full sentences, complex grammar
Mastery, not minutes
We don't reward long sessions. The parent dashboard surfaces words your child can actually retrieve unaided — words they will still know in three months — not how many cards they clicked through today. A short consistent habit beats a marathon every time.
- "Words mastered" = retrieved correctly after 21+ days without review
- Streaks are protected by a daily 5-minute floor, not a 30-minute one
- Time-on-task is shown to parents but isn't a goal metric in-app
- Long sessions don't unlock anything special — short habits do