f(x) Calc vs MistakeBook
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
f(x) Calc
A full-featured scientific calculator designed for math and science students. It offers natural math entry and includes built-in examples to aid learning. A simplified Junior mode is available for everyday use.
- Natural Maths entry
- Built-in learning examples
- Junior mode for everyday use
- Ideal for math and science study
- Full-featured scientific calculator
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Full-featured Scientific Educational calculator with Natural Maths entry. Ideal for Maths and Science study with a built-in examples that will help you to learn how to use your calculator. The perfect backup when you don't have your school calculator. Try the Junior mode for every-day use, with easy access to the most essential functions.
MistakeBook
Log and review incorrect answers to improve learning. Organize mistakes by subject and topic, and utilize spaced repetition to reinforce weak areas. Track progress with visual charts and daily check-ins for effective test preparation.
- Log mistakes with photos and notes
- Organize by subject and custom tags
- Spaced repetition review mode
- Ebbinghaus forgetting curve schedule
- Progress charts and stats dashboard
- Data import/export backup
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Capture every wrong answer in seconds. Sort mistakes by subject, tag key topics, and build a personal error bank—no account required. Preparing for midterms, finals, or standardized tests? Spaced review quizzes follow the forgetting curve so weak spots come back at the right time. See progress charts and daily check-ins to stay on track. • Log mistakes with photos, notes, and difficulty tags • Organize by subject, chapter, and custom tags • Review mode: quiz, practice, and spaced repetition • Ebbinghaus schedule for smarter recall • Stats dashboard: mastery trends and weak areas • Import/export backup—data stays on your device Built for students who want a simple, private way to turn errors into higher scores.
Screenshots
Verdict
The clearest difference is price: f(x) Calc at Free against MistakeBook's $1.99. f(x) Calc also leads on update cadence (every 10 days vs monthly). MistakeBook's advantage is in-app purchases (none vs 1) and iOS requirement (13.0 vs 16.6). On ads 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
f(x) Calc is free to download; MistakeBook costs $1.99 up front. f(x) Calc sells 1 one-off in-app purchase. MistakeBook asks for nothing beyond the download.
f(x) Calc ships an update every 10 days, MistakeBook monthly. Both last shipped on October 31, 2026.
| Parameter | f(x) Calc | MistakeBook |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 5.0 (1 ratings) — better | — |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 1 — better | — |
| Update frequency | Every 10 days — better | Monthly |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free — better | Paid |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 16.6 | 13.0 — better |
| Further details — not scored | ||
| Size | 5 MB | 26 MB |
| Age rating | 4+ | +4 |
| Developer | David Russell | Xiamen City Fanyou Network Technology Co., Ltd. |
Customer experience
f(x) Calc
MistakeBook
In-app purchases
f(x) Calc
- Full AccessFree
MistakeBook
No in-app purchases
