Crestellar Academy

The all-in-one HKDSE Maths self-study app for iPhone and iPad — real 名校 exam questions, timed mock exams, past-paper solutions, revision notes, and every subject's 5** cutoff since 2012. Free to start, no account needed.

NOW ON iPHONE • The whole app on your phone: quizzes, mock exams, long questions, past papers, notes, the timetable and Home Screen widgets, laid out for a phone — one account, one subscription, both devices • Writing on the question stays iPad-only for now

PRACTICE ENGINE • Thousands of real MC and long questions from Hong Kong's top schools — filter by year, topic and difficulty, or take on the out-of-syllabus Challenging tier • Timed S1–S6 mock exams that mirror the real HKDSE Paper 2, slot by slot • Instant marking with a grade estimate, per-question review, per-topic time and accuracy • DSE LEVEL PREDICTOR: your mock score is converted using the REAL cut-offs from the last five years of HKDSE Mathematics — see where you sit and how many more questions reach the next level. • One-tap drill on your weakest topic • Long-question sessions: 5–50 per session, unseen questions first • Save questions to revisit; share a result card in one tap

5** SOLUTIONS • Every question has a complete marking-scheme solution — natively typeset, never a scan • Max plans unlock advanced solutions: faster 5** techniques, exclusive calculator programs, and Typical Questions & Skills for all 19 chapters

WRITE ON THE QUESTION (iPad) • In a timed quiz, the Long Question bank or any saved question: pen, dotted pen, highlighter and eraser, pinned to the figure so they scroll and zoom with it — or pull up a blank scratch sheet • Hold at the end of a stroke and it snaps perfect — lines, circles, rectangles, triangles, parabolas — then drag its corners; one undo puts your freehand back • Apple Pencil always draws and double-tap swaps to the eraser; workings are never stored

VISUAL MATH LAB • 43 interactive topics across three papers — Compulsory Part (21 labs), M1 Calculus & Statistics (12 labs: exponential growth, maxima & minima, trapezoidal rule, Bayes' theorem, random variables, binomial/geometric/Poisson, normal distribution, Central Limit Theorem, confidence intervals and 3 shared) and M2 Algebra & Calculus (13 labs: linear systems, matrices, vectors, limits, curve sketching, related rates, integrals, volumes, trig identities, binomial theorem, induction) — drag real DSE figures, watch the maths respond • Every lab runs on iPhone and iPad; AM–GM, Circle Angle Theorems, M2 Systems of Linear Equations and M1 Central Limit Theorem are free with no account; the rest are free to read — upgrade to interact

REVISION TIMETABLE • Plan all 25 HKDSE subjects — official names, papers and topics; drag to build your week, clashes nudge to the nearest free slot • Revision, test, mock and homework blocks with optional reminders; "Build my week" fills your free hours; a Progress tab tracks mastery

STAY ON TRACK • Home Screen widgets on iPhone and iPad: your practice streak and grade trend, a live HKDSE countdown, or today's revision plan • In the app: the same countdown, streak and grade trend, plus an optional evening study reminder • Every attempt saved with full per-topic history

FREE TOOLS (no login needed) • HKDSE cutoff scores: 16 subjects, every year since 2012, in interactive charts • Past-paper solutions and complete illustrated revision notes, natively typeset • Guest mode: your first question 30 seconds after downloading

FAIR PRICING • 80 free tokens every month, on every account — the free tier is real • Top-up token packs that never expire • Plus, Pro and Max plans cost a fraction of one tutoring lesson

Fully bilingual — switch between English and Traditional Chinese any time.

Built by Hong Kong DSE Maths teachers. Download free and aim for your 5**.

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