Comparison

Bopomofo vs Math Key

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Bopomofo

Practice Bopomofo, a phonetic system primarily used in Taiwan. This application allows you to save your practice sessions. It's designed for learning and reinforcing Chinese phonetic symbols.

Highlights
  • Bopomofo practice
  • Save practice sessions
  • Taiwanese phonetic symbols
  • Educational tool
Features
Read full description

Learn Zhuyin (Bopomofo), the phonetic symbols used in Taiwan to write the pronunciation of Mandarin Chinese, by writing them yourself. Just trace over the light guide letter with your finger or Apple Pencil. FEATURES - All 37 Zhuyin symbols (21 initials and 16 finals) - Pick any symbol from the home screen to start practicing - Handwriting practice by tracing over guide letters on a practice grid - Romanization and category shown for each symbol - Erase with the trash button and write again - Move to the previous / next symbol with the arrow buttons - Save your writing to the Photos app GREAT FOR - Beginners of Mandarin Chinese - Travelers and students going to Taiwan - Children practicing Zhuyin This app is free and contains ads.

About

Math Key

Features
Read full description

Math Keyboard is a fast custom keyboard that lets you type mathematical notation in any app: Notes, Mail, Messages, Pages, homework apps and more. WHAT YOU GET - 300+ mathematical symbols organised into clear pages: basic operators, fractions, powers and indices, Greek letters, geometry, set theory, calculus and units - Fractions and superscripts that paste as real Unicode characters, so they look right everywhere - A starred page for your own custom keys: save the symbols and snippets you use most, reorder them by long-press, delete by swipe - Designed for students, teachers and anyone writing maths on iPhone or iPad - Covers the notation used in the Singapore PSLE syllabus, as well as secondary and university level maths PRIVACY FIRST This keyboard does not request Full Access. It never collects, uploads or records anything you type. Everything stays on your device. FIVE LANGUAGES Available in English, Simplified Chinese, Japanese, Korean and French. The keyboard follows your system language automatically. HOW TO ENABLE Open Settings, then General, then Keyboard, then Keyboards. Tap Add New Keyboard and choose Math Keyboard. Then long-press the globe key in any text field to switch to it. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Also: https://mathkeyboard.1stshop.sg/terms.html Privacy Policy: https://mathkeyboard.1stshop.sg/privacy.html

Screenshots

Bopomofo4 screens
Math Key4 screens

Verdict

The call

The clearest difference is price: Bopomofo at Free against Math Key's $1.99. Bopomofo also leads on iOS requirement (15.6 vs 17.0). Math Key's advantage is ads (none vs shown) and update cadence (every 3 weeks vs every 70 months). On 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

CostPrice · In-app purchases · Ads · Monetization

Bopomofo is free to download; Math Key costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Bopomofo ships an update every 70 months, Math Key every 3 weeks. The most recent releases landed on October 18, 2026 and October 6, 2026 respectively.

Scorecard4 real differences · 6 level
Bopomofo versus Math Key: the parameters behind the verdict, then further details
ParameterBopomofoMath Key
PriceFree — better$1.99
Rating2.0 (3 ratings) — better—
Positive reviews0.0% of reviews—
Number of ratings3 — better—
Update frequencyEvery 70 monthsEvery 3 weeks — better
AdsYesNo — better
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.6 — better17.0
Further details — not scored
Size4 MB1 MB
Age rating4+4+
DeveloperKiyoshi Koike1STGROUP PRIVATE LIMITED

In-app purchases

None

Bopomofo

No in-app purchases

None

Math Key

No in-app purchases

Questions

Is Bopomofo free?
Bopomofo is free to download, with no in-app purchases.
Is Math Key free?
Math Key costs $1.99, with no in-app purchases.
Do Bopomofo or Math Key have ads?
Bopomofo shows ads; Math Key does not.
Which is updated more often, Bopomofo or Math Key?
Bopomofo ships an update every 70 months, and Math Key every 3 weeks. Most recently, Bopomofo was updated on October 18, 2026 and Math Key on October 6, 2026.

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