Test your mental math skills by quickly determining if the result of an on-screen operation is even or odd. Earn more points for faster answers and challenge friends to see who has the quickest mind. The difficulty increases as you progress.






250+ iOS apps & games curated and reviewed
Looking for free quadsum apps and games? 20 of our 250+ tracked titles are free to download — no subscription, no trial. The rest are premium picks worth paying for.
| # | App | Price | Rating | Ads | In-App Purchases | Updated | |
|---|---|---|---|---|---|---|---|
| 1 | Free | — | No | Yes | Sep 2026 | ||
| 2 | Free | — | No | No | May 2026 | ||
| 3 | Free | 4.4★ (107K) | Yes | Yes | Oct 2026 | ||
| 4 | Free | 2.2★ (6) | No | No | Oct 2026 | ||
| 5 | Free | — | No | No | Sep 2026 | ||
| 6 | Free | — | Yes | Yes | Sep 2026 | ||
| 7 | Free | 4.6★ (31K) | Yes | Yes | Oct 2026 | ||
| 8 | Free | 4.8★ (30K) | Yes | Yes | Oct 2026 |






Test your mental math skills by quickly determining if the result of an on-screen operation is even or odd. Earn more points for faster answers and challenge friends to see who has the quickest mind. The difficulty increases as you progress.










Strategically place diverse block shapes to solve puzzles and clear lines or squares. Enjoy multiple game modes, from relaxing to challenging, with a sleek, minimalist design that trains your brain.