The all-in-one DSE Maths self-study app 一App搞掂DSE數學
Now on iPhone Real 名校 exam questions, timed mock exams, an interactive Visual Math Lab, revision notes, a revision timetable for all 25 subjects, and every subject's 5** cutoff since 2012 — on your iPhone and your iPad, one account. iPhone版新登場 名校試題、計時模擬試、數學動態實驗室、溫習筆記同25科溫習時間表、2012年起各科5**分數線 — iPhone同iPad都用得，一個帳戶。
Now on iPhone — one account, both devicesiPhone版新登場 — 一個帳戶，兩部機都用得
Every screen is laid out for a phone: practice quizzes, timed mock exams, the Long Question bank, past-paper solutions, revision notes, the Visual Math Lab, HKDSE cutoffs, the Revision Timetable and the calculator programs. Your iPad account, subscription and tokens carry over — sign in on whichever device is in your hand. 每個畫面都重新排過版啱電話熒幕：操卷、計時Mock卷、長題目題庫、歷屆試題詳解、溫習筆記、數學動態實驗室、HKDSE分數線、溫習時間表同計數機Program。iPad上嘅帳戶、訂閱同token全部通用 — 邊部機喺手就用邊部。
- One account, one subscription — iPhone and iPad, signed in on one device at a time.一個帳戶、一份訂閱 — iPhone同iPad都用得，同一時間一部機登入。
- All three Home Screen widgets — day streak & grade trend, the HKDSE countdown and today's plan.三款主畫面小工具 — 連勝同成績趨勢、HKDSE倒數、今日溫習計劃。
- Free to start — guest mode, the cutoff tool and four Visual Math Lab topics need no account on either device.免費開始 — 訪客模式、分數線工具同四個數學動態實驗室，兩部機都唔使開戶口。
- Writing on the question stays iPad-only for now — it follows on iPhone in a later update.題目上手寫暫時只喺iPad有 — 稍後更新會加入iPhone版。
Everything inside the appApp入面嘅所有功能
Ten tools, one app — from first practice question to results-day cutoff check. 十大功能，一App齊晒 — 由第一條練習題操到放榜睇分數線。
MCQ practice quizzes & timed mock examsMCQ練習同計時Mock卷
Choose exactly what to drill — form (S1–S6), topic, sub-topic and difficulty — or sit a full timed mock exam blueprinted on the real HKDSE Paper 2. The wall-clock timer keeps exam pressure honest, you can flag questions to revisit before submitting, and challenge mode serves the toughest beyond-syllabus problems. 自選年級（S1–S6）、課題、子課題同深淺操卷，或者直接考一份跟足HKDSE卷二藍圖嘅計時Mock卷。計時器跟足真考試節奏，唔肯定嘅題目可以先標記、交卷前再返轉頭做，仲有挑戰模式俾你操超綱難題。
Instant marking, estimated level, deep analysis即批、估等級、深入分析
Submit and the result is ready instantly: an estimated DSE level with a score ring, the full answer sheet showing exactly where you slipped, model answers for every question, time-and-accuracy charts by topic, and a one-tap drill on your weakest topic. Every attempt is saved to Quiz Records, and a branded result card is ready to share with classmates. 一交卷即刻有結果：估算DSE等級同分數環、逐題答案紙睇清楚邊度失分、每題model answer、逐課題時間同準確度圖表，仲可以一掣操弱項。每次紀錄自動保存喺Quiz Records，成績卡仲可以即刻分享俾同學。
Visual Math Lab — see the maths move數學動態實驗室 — 拖一下，數學郁畀你睇
43 interactive topics: drag, slide and rotate real DSE figures and watch the maths respond live. Each lab covers its whole chapter's exam question types, named exactly as the revision notes name them — and every revision-note chapter links straight to its own lab. Four labs are completely free, even without an account. 43個互動課題：拖得、轉得、玩得，真DSE圖形即時有反應。每個實驗室覆蓋成章考試題型，名稱同溫習筆記完全一致，喺筆記仲可以一撳直達。四個實驗室完全免費，唔使開戶口都玩得。 The Lab now opens on a subject picker: Compulsory Part (21 labs across 6 strands), M1 · Calculus & Statistics (12 labs — exponential growth and decay, maxima and minima, the trapezoidal rule, Bayes' theorem, discrete random variables, the binomial, geometric and Poisson distributions, the normal distribution, the Central Limit Theorem and confidence intervals, plus three labs it shares with the other papers) and M2 · Algebra & Calculus (13 labs filling all five M2 strands — from systems of linear equations, matrices and vectors to limits, first principles, curve sketching, related rates, indefinite and definite integration, volumes of revolution, trigonometric identities, the binomial theorem and induction). 實驗室而家一入去就揀卷：必修部分（6個範疇、21個實驗室）、M1 · 微積分與統計（12個實驗室 — 指數增長與衰減、極大值與極小值、梯形法則、貝葉斯定理、離散隨機變量、二項／幾何／泊松分佈、正態分佈、中心極限定理、置信區間，另有3個同其他卷共用）同M2 · 代數與微積分（13個實驗室，5個範疇全開 — 線性方程組、矩陣與行列式、空間向量、極限與導數、基本原理與重要極限、曲線描繪、相關變率、不定積分法、定積分的性質、旋轉體體積、三角恆等式、二項式定理、數學歸納法）。 All 43 labs run on iPhone and iPad — the free ones need no account at all. 43個實驗室iPhone同iPad全部用得，免費嗰幾個更加唔使開戶口。
Revision Timetable — plan all 25 subjects溫習時間表 — 25科一齊排
A weekly planner for every HKDSE subject, not just Maths — official subject names, papers and topic lists built in. Drag sessions around your week (a clash slides to the nearest free slot), set reminders, tick sessions off — or let "Build my week" fill your free hours in one tap. A Home Screen widget shows today's plan. 唔止數學 — 25科HKDSE科目全部排得到，官方科目名、卷別、課題清單齊備。拖拉排時間表，撞時間自動搵最近空檔；可設提醒、做完打勾，仲有「一鍵排一週」自動填滿你嘅空閒時間。主畫面小工具直接睇到今日計劃。
Real 名校 Long Question Bank名校長題目題庫
A deep bank of long questions in the real exam format, organised by topic, sub-topic and difficulty, in English and Chinese. Read the question, attempt it on paper, then flip to the full marking-scheme solution — natively typeset, razor-sharp at any zoom, with pinch-to-zoom for the fine print. 大量真考試格式嘅名校長題目，按課題、子課題、深淺分類，中英對照。睇題、落筆做，再翻去完整marking scheme解答 — 原生排版，放大幾多倍都清晰。
Advanced Solutions — beyond the marking scheme進階解法，唔止標準答案
Max plans unlock a second solution for every question: the faster 5** method — clever setups, time-saving techniques and calculator-program shortcuts, with common traps called out before you fall into them. Standard marking-scheme solutions remain on every paid plan. Max計劃每題解鎖多一份解法：5**快速做法 — 聰明設題、慳時間技巧、計數機program捷徑，仲會預先提你常見陷阱。標準marking scheme解答就每個付費計劃都有。
Complete notes + Typical Questions & Skills全課題筆記連題型攻略
Natively typeset revision notes for every syllabus topic — definitions, formulas, worked examples, common-mistake callouts and proper figures. Max plans add Typical Questions & Skills: every exam question type across 19 chapters, walked through step by step the exam-script way. 全課題原生排版筆記 — 定義、公式、例題、常見錯誤提示同精美插圖。Max計劃再加題型攻略：19章每一種考試題型，一步一步exam-script式教你做。
Past-paper solutions, beautifully retypeset歷屆試題詳解，全新排版
HKEAA marking schemes rebuilt natively — no blurry scans: Paper 1 solutions question by question with marks and remarks, the full Paper 2 answer key with answer rates, the general marking guidelines, and highlights from the examiners' report. HKEAA評卷參考原生重排 — 唔係模糊影印本：卷一逐題詳解連分數同註解、卷二全份答案連答對率、評卷總則，仲有考試報告重點。
HKDSE Cutoff — every subject since 2012HKDSE分數線 — 2012年起每一科
Level cutoffs from 5** down to 2 for 16 subjects, 2012–2025, as a clean table and an interactive chart — percentage headline with the raw threshold underneath. Completely free, no login, updated every results day. 16科由2012到2025年嘅等級分數線（5**至2），一表一互動圖 — 百分比做主角、原始分數喺下面。完全免費、唔使login，每年放榜日更新。
Calculator programs that save whole minutes計數機Program，一分一秒都慳
Step-by-step input guides for fx-50FH II calculator programs — quadratic equations, circle equations, loci and more — plus demos showing exactly when to fire each program inside a real exam question. fx-50FH II計數機program逐步輸入教學 — 二次方程、圓方程、軌跡等等 — 連示範教你喺真題入面幾時用邊個program最著數。
Simple plans, honest free tier收費簡單，免費都好用
Every plan unlocks the same app — plans differ in monthly ⚡ tokens and solution depth. Prices are what the App Store charges in Hong Kong. 所有計劃都係同一個App — 分別在於每月⚡token數量同解答深度。價錢即係香港App Store收費。
- Guest mode — try before you even sign up訪客模式 — 唔使開戶口都試到
- 80 ⚡ tokens every month for practice每月80個⚡token做練習
- HKDSE Cutoff — 16 subjects, no login neededHKDSE分數線 — 16科，唔使login
- Past-paper solutions & complete revision notes歷屆試題詳解同全課題溫習筆記
- Quiz records & saved questions試後紀錄同收藏題目
- Everything in FreeFree全部功能
- Full Long Question bank with marking-scheme solutions全長題目題庫連marking scheme解答
- MCQ practice quizzes with instant markingMCQ練習即做即批
- S1–S6 mock exams on the real Paper 2 blueprintS1–S6跟真卷藍圖嘅Mock卷
- Per-topic exam analysis & weakest-topic drills逐課題成績分析同弱項特訓
- Calculator programs (Plus / Pro)計數機Program（Plus / Pro）
- Everything in PlusPlus全部功能
- 3× the tokens — enough for daily practice3倍token — 日日操都夠用
- Everything in ProPro全部功能
- Advanced 5** solutions on every question每題5**進階解法
- Typical Questions & Skills — all 19 chapters題型攻略 — 全19章
- Max calculator programsMax計數機Program
- Early access to new features新功能早鳥試用
- Everything in Max 5×Max 5×全部功能
- 4× the tokens — practice without counting4倍token — 操到唔使數住用
- Built for the final sprint to the exam為考前衝刺而設
⚡ Token top-up packs are also available inside the app. Subscriptions are billed and managed through your Apple ID; monthly ⚡ token allowances are identical on monthly and annual billing. App內另有⚡token加購包。訂閱經Apple ID收費同管理；無論月費定年費，每月⚡token數量一樣。
Frequently asked questions常見問題
What is Crestellar Academy?Crestellar Academy係咩？
Does it cover the Compulsory Part of HKDSE Mathematics?係咪包HKDSE數學必修部分？
What resources are on Crestellar Academy?App入面有咩資源？
- Long Question Bank — extensive HKDSE-style long questions by topic, sub-topic and difficulty, each with a full marking-scheme solution (and an advanced solution on Max)長題目題庫 — 大量HKDSE式長題目，按課題、子課題、深淺分類，每題連完整marking scheme解答（Max再有進階解法）
- MCQ Practice Quizzes — timed quizzes across every topic and difficulty, with instant feedbackMCQ練習 — 覆蓋每個課題同深淺嘅計時測驗，即做即批
- Mock Exams — simulated S1–S6 papers on the real Paper 2 blueprint, for readiness and time managementMock卷 — S1–S6跟足真卷二藍圖嘅模擬試，練實力又練時間分配
- Past-paper solutions — HKEAA marking schemes natively retypeset, with the Paper 2 answer key and examiners' report highlights歷屆試題詳解 — HKEAA評卷參考原生重排，連卷二答案同考試報告重點
- Revision notes — complete natively-typeset notes, plus Typical Questions & Skills on Max溫習筆記 — 全課題原生排版筆記，Max再加題型攻略
- Visual Math Lab — 43 interactive topics (Compulsory Part, M1 and M2) where you drag real DSE figures and watch the maths respond; four labs free for everyone數學動態實驗室 — 43個互動課題（必修部分、M1同M2），拖真DSE圖形睇數學即時反應；四個實驗室人人免費
- Revision Timetable — a drag-and-drop weekly planner for all 25 HKDSE subjects, with reminders, a one-tap week builder and a Home Screen widget溫習時間表 — 25科HKDSE科目拖拉即排嘅週計劃，連提醒、一鍵排一週同主畫面小工具
- HKDSE Cutoff — level cutoffs for 16 subjects since 2012, free for everyoneHKDSE分數線 — 16科由2012年起嘅等級分數線，人人免費
- Calculator Programs — beginner-friendly guides for entering and using each program effectively計數機Program — 新手都跟到嘅輸入同應用教學
- Full English and Traditional Chinese interface全英文／繁體中文介面