Grade 9 Math Mastery vs Skim
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Grade 9 Math Mastery
Read full descriptionHide full description
Grade 9 Math Mastery prepares Ontario students for the province-wide Grade 9 mathematics assessment. It teaches each concept first, then gives 400 practice questions to prove it stuck. Most study apps only test. This one teaches. Learn the concept • 25 guided lessons, one for every topic on the course • Worked examples that reveal one step at a time, so students can attempt the next line before seeing it • Each lesson names the mistakes students actually make, and why they happen • A short check at the end confirms the idea landed Practise until it sticks • 400 questions across all five strands: Number, Algebra, Data, Geometry and Measurement, and Financial Literacy • Difficulty adapts to the student and moves up as they improve • Wrong answers come back automatically on a spaced repetition schedule, timed for just before they would be forgotten • A mistake journal collects everything missed, with step-by-step solutions • A 57-formula reference sheet, plus a quiz mode for memorising it Practise under real conditions • Mini and full mock tests, timed • A full exam simulation: 25 questions, 75 minutes, no hints, with a complete review afterwards • An estimated achievement level after every attempt Keep them coming back • Speed Drill, Survival, Race Mode, and a two-player duel on one device • A new challenge question every day • Streaks, daily goals and 21 achievements See exactly where they stand • Mastery across all 25 topics at a glance • A predicted achievement level, and the specific topics holding it back • Weekly progress reports and an exam-readiness checklist • A parent view, plus a progress summary you can share or email For parents Everything is built around one question: what should they work on next? The app answers it on every screen, names the topics that need attention, and links straight to the lesson that teaches them. You do not need to remember Grade 9 math to help. Free and Premium Algebra is free, with 15 practice questions a day and one mini mock test. Premium unlocks all five strands, every guided lesson, unlimited daily practice, full mock exams and the exam simulation, and parent reports. Works on iPhone and iPad. Premium starts with a 7-day free trial. Cancel any time. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period. Payment is charged to your Apple Account. Manage or cancel in your Apple Account settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Terms of Service: https://eager.app/terms Privacy Policy: https://eager.app/privacy
Skim
Transform documents into bite-sized learning cards with AI. Choose from four learning modes, ask questions about terms, and track your progress. Ideal for students, researchers, and professionals.
- AI-generated learning cards
- Multiple learning modes (Deep Understanding, ELI5, Memorize, Quick Review)
- Ask AI questions about document terms
- Progress tracking (streak, mastery, accuracy)
- Supports PDF, Word, PowerPoint, text, and Markdown
- No ads or data tracking
Read full descriptionHide full description
Pick how you want to learn: Deep Understanding, ELI5, Memorize, or Quick Review. Skim's AI breaks the document into bite-sized cards in that mode. Upload any document — PDF, Word, PowerPoint, plain text, or Markdown and get tailored cards. Swipe any term to ask Skim about anything unclear, quiz yourself to see what stuck, and track your progress along the way. Same dopamine, actually useful. HOW IT WORKS 1. Upload a PDF, slide deck, doc, or notes 2. Skim's AI breaks it into bite-sized cards — each focused on a single idea 3. Swipe through. Tap any term to ask Skim for a deeper explanation 4. Quiz yourself to see what actually stuck 5. Track your streak and watch your progress unlock GREAT FOR • Students prepping for exams or working through textbooks • Researchers digesting papers and reports • Professionals navigating contracts, briefs, manuals, and decks • Self-learners working through online courses and books • Anyone who's collected docs they meant to read FOUR WAYS TO LEARN • Deep Understanding — comprehensive, concept-first • ELI5 — plain language and analogies • Memorize — quiz-dense, atomic facts for recall • Quick Review — punchlines only, for the refresh ASK SKIM ANYTHING Tap any term in a card for an instant explanation. Or type a follow-up question — Skim's AI assistant stays grounded in what the document actually says, so every answer ties back to your source. TRACK YOUR PROGRESS • Reading streak counter • Card mastery % per document • Quiz accuracy that finds your weak spots • Weekly activity at a glance SUPPORTED FORMATS PDF, PowerPoint (.pptx), Word (.docx), plain text (.txt), Markdown (.md) AI may make mistakes — Skim's cards are reading aids, not authoritative answers. Verify critical information against your source. PRO ($6.99/month or $69.99/year) • Unlimited document processing • 140 AI assistant questions per month ULTRA ($13.99/month or $139.99/year) • Everything in Pro • 280 AI assistant questions per month Cancel anytime in iOS Settings. PRIVACY FIRST No ads. No tracking. No selling your data. Your documents stay yours. Read our full policy at https://tryskim.app/privacy. Privacy Policy: https://tryskim.app/privacy Terms of Use: https://tryskim.app/terms Support: hello@tryskim.app
Screenshots
Verdict
The clearest difference is update cadence: Skim at every 2 weeks against Grade 9 Math Mastery's every 5 months. On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Grade 9 Math Mastery sells 2 in-app purchases, starting at $4.99 per month and Skim sells 4 in-app purchases, starting at $6.99 per month. Whichever you choose, the download price is not the number that matters.
Grade 9 Math Mastery ships an update every 5 months, Skim every 2 weeks. The most recent releases landed on October 15, 2026 and October 7, 2026 respectively.
| Parameter | Grade 9 Math Mastery | Skim |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (3 ratings) — better |
| Number of ratings | — | 3 — better |
| Update frequency | Every 5 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | — | Freemium |
| Devices | iPhone, iPad — better | iPhone |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 7 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Eager.app | DORUK SAVASAN |
In-app purchases
Grade 9 Math Mastery
- Grade 9 Math Mastery — Monthly$4.991 Month
- Grade 9 Math Mastery — Annual$29.991 Year
Skim
- Pro Monthly$6.991 Month
- Ultra Monthly$13.991 Month
- Pro Annual$69.991 Year
Show 1 moreShow fewer
- Ultra Annual$139.991 Year
Questions
Is Grade 9 Math Mastery free?
Is Skim free?
Do Grade 9 Math Mastery or Skim have ads?
Which is updated more often, Grade 9 Math Mastery or Skim?
Other comparisons















