Preposition Builder Master Pro vs (Open Source) Mental Math
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Preposition Builder Master Pro
Learn English prepositions and grammar by correctly placing words to form sentences and common sayings. This game offers multiple difficulty levels, from beginner to expert, and includes a fun way to master idioms and expressions. Compete with others or practice solo to improve your language skills.
- Sentence building with prepositions
- Multiple difficulty levels (Beginner to Expert)
- Proverbs and Sayings level
- Time penalties for errors
- Scoring based on speed and accuracy
- Online multiplayer mode
- Game Center integration
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Learn prepositions in English and grammar by putting the prepositions in place to form correct sentences and sayings. Preposition Master is a fun and educational game for kids and English language students of all ages who want to learn and improve their language skills in a more entertaining way. How do you play? It’s easy. The game consists of putting the prepositions from each level in the correct place to form a correct sentence. (Beginner, competent, professional, expert, sayings.) If you make a mistake and click the incorrect preposition, there is a time penalty. Once you have completed the sentence you will receive a score based on how fast you were and your total number of errors. You can share your knowledge with other players worldwide thanks to online multiplayer mode or with your friends on Game Center. Are you an English expert who wants to show off your skills? Are you an English student who wants to improve your skills? Preposition Master will help you use prepositions in sentences correctly. Preposition Master is the first game of its kind designed and developed completely by educators to help students improve one of the biggest problems language learners all face, correct use of prepositions. With four levels from beginner to expert, Preposition Master is a challenge for everyone from the Beginner to the most seasoned English language communicators. The Proverbs and Sayings level is a great way to learn and remember popular English idioms and expressions. These are the levels: Beginner: Ideal for children. This level contains the easiest sentences with the fewest prepositions to work with. Competent: This is where things start to get harder. This level is great for learners who are a bit farther along in their English language learning adventure. Professional: Great for users with a solid base in English who want to keep their skills up to date. Expert: Only for those with the most proficient English skills. Are you one of them? Do you have what it takes to become the next Preposition Master? Try your luck in single player mode or against friends and other players worldwide. Learn English with a smile on your face.
(Open Source) Mental Math
This application offers a free, open-source platform for practicing mental arithmetic. It features timed tests, custom drills, and a comprehensive library of mental math tricks. All content is available offline without ads or paywalls.
- Timed arithmetic tests
- Customizable drills
- Mental math tricks library
- Offline progress tracking
- Multiple operation types
- Fast session interface
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A free, open-source mental math trainer. No ads, no paywalls, no locked content — every exercise and difficulty is included. Sharpen your arithmetic with quick timed tests, custom drills, and a library of mental-math tricks. Everything runs offline and your progress stays on your device. FEATURES Timed Tests A daily 60-second challenge plus sprints, a two-minute marathon, per-operation tests, and a hard mixed test — at four difficulty levels, each with best scores. Custom Trainer Pick a number domain (Times tables, Natural, Decimal, Money, Huge), choose one or more exercises, and set per-exercise difficulty from Easy to Super hard. All the Operations Addition, subtraction, multiplication, division, squares, square roots, fractions, percentages, and modulo. Mental Math Tricks Dozens of step-by-step tricks for faster addition, subtraction, multiplication, division, and squares — with worked examples and favorites. Practice Any Trick Every trick comes with a 60-second drill built for it: × 11 drills, squares ending in 5, numbers near 100, and more. Magic Square A number puzzle: make every row, column, and diagonal add up to the same total. Four levels, from 1-9 up to bigger number sets. Progress Tracking Solved totals, accuracy, best run, daily streak, longest streak, and a weekly activity view. Fast Sessions An on-screen keypad with instant answer checking and haptics. No ads. No paywalls. No account required. 100% Open Source The complete source code is public - see it, audit it, or contribute at https://github.com/Open-Apps-Studio/mental-math
Screenshots
Verdict
The clearest difference is rating: Preposition Builder Master Pro at 3.8 against (Open Source) Mental Math's 3.0. Preposition Builder Master Pro also leads on ratings volume (17 vs 2). (Open Source) Mental Math's advantage is monetization model (free vs paid). On price, review sentiment, update cadence and ads 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. Neither carries in-app purchases, so what you see is what you pay.
Preposition Builder Master Pro holds the better App Store score, 3.8 against 3.0. That said, the two scores are not equally well evidenced: Preposition Builder Master Pro has 17 ratings behind it against 2, so its average is the more settled of the two. Written reviews split almost evenly too, at 0% and 0% positive.
Preposition Builder Master Pro ships an update every 2 months, (Open Source) Mental Math every 5 weeks. The most recent releases landed on October 9, 2026 and October 6, 2026 respectively.
| Parameter | Preposition Builder Master Pro | (Open Source) Mental Math |
|---|---|---|
| Price | Free | Free |
| Rating | 3.8 (17 ratings) — better | 3.0 (2 ratings) |
| Positive reviews | 0.0% of reviews | 0.0% of reviews |
| Number of ratings | 17 — better | 2 |
| Update frequency | Every 2 months | Every 5 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 16.4 |
| Further details — not scored | ||
| Size | 45 MB | 41 MB |
| Age rating | 4+ | 4+ |
| Developer | Imanol Fernandez Gorostizaga | AHMET EMRE DEDELER |
Customer experience
Preposition Builder Master Pro
(Open Source) Mental Math
In-app purchases
Preposition Builder Master Pro
No in-app purchases
(Open Source) Mental Math
No in-app purchases
Questions
Is Preposition Builder Master Pro free?
Is (Open Source) Mental Math free?
Which has better reviews, Preposition Builder Master Pro or (Open Source) Mental Math?
Do Preposition Builder Master Pro or (Open Source) Mental Math have ads?
Which is updated more often, Preposition Builder Master Pro or (Open Source) Mental Math?
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