Three months after launching daily puzzles on the web, we put them on the home screen — same UK-day logic habits, built for the five-minute ritual before homework.
In February we launched three daily maths puzzles on the web — Cryptarithm, Magic Square, and Summit. We explained why we built them: short logic habits for competition students, not another worksheet stack.
By spring, the pattern was clear. Students who liked the dailies were opening them on the bus, in the car before tutoring, on a shared family iPad. The puzzles worked. The friction was the browser — bookmarks, tabs, remembering to come back.
In mid-May 2026 we released Problems.cc on the App Store for iPhone and iPad. Same three games. Same UK calendar day. A home-screen ritual instead of another link to remember.
Why we did not stop at mobile web
The web version was always the source of truth. We were not trying to replace it.
We wanted a place where a student could tap one icon, play five minutes, close the app, and find tomorrow’s puzzle waiting — without hunting through Safari history.
For olympiad-minded families, that small difference matters:
- Habit sticks when the entry point is obvious. A daily puzzle on the home screen behaves like Wordle, not like “that maths site we used once”.
- Progress should survive the session. Leave mid-puzzle, switch apps, come back later — your draft and your streak should still be there.
- Optional sync across devices. Play on a phone, continue on an iPad, sign in when you want account-backed history on problems.cc as well.
The app is not a separate product. It is the same daily layer we described in February, packaged for how children actually use a screen.
What is in the app
| Game | What you get |
|---|---|
| Cryptarithm | Letter-for-digit puzzles from our verified pool — one per day |
| Magic Square | 3×3 balance grids with a magic sum that changes by date |
| Summit | Countdown-style targets with weekday variety in allowed operations |
Plus:
- A full archive of past days — miss Tuesday, replay it on Saturday
- Streaks and progress without forcing sign-up
- Light and dark theme
- No ads and no pre-game interruptions
We kept the scope narrow on purpose. The App Store is full of maths apps that try to be everything: drills, videos, gamified coins, subscription walls. We wanted one thing done well — five minutes of structure before homework or past-paper work.
What we learned after February
The first article argued that competition preparation has a gap between arithmetic apps and full olympiad papers. Three months of daily puzzles on the web confirmed it.
Students who rotated through the three games started carrying constraint language into lessons: “that letter can’t be zero”, “the centre cell fixes the rest”, “try brackets on Thursday”. Parents reported something simpler — a maths ritual that did not require printing or supervising.
The app was the natural next step: keep the pedagogy, remove the “open the right tab” step.
Web or app — what to use
| Situation | Use |
|---|---|
| Quick play on any device, no install | problems.cc/games |
| Daily habit on a child’s iPhone or iPad | App Store |
| Past papers, practice sets, full problem archive | Web at problems.cc |
Same puzzles each UK day whether you play in the app or the browser. Sign in on both if you want solves and in-progress drafts aligned.
How to build the habit on a phone
- Download once, pin the ritual — same time each day beats “whenever we remember”.
- Start with one game — rotate Cryptarithm, Magic Square, and Summit across the week, as in our February protocol.
- Treat five minutes as enough — the app is a warm-up, not a replacement for teaching or past papers.
- Use the archive without guilt — streaks are motivating; replaying a missed day is still practice.
- Keep depth on the web — competition papers and curated sets stay on problems.cc; the app holds the daily layer.
What we are not claiming
This is not “put your child on an iPad and call it olympiad prep”. It is not a drill app dressed up as logic training.
It is a small, repeatable constraint workout — now on the device students already reach for — sitting in the same middle ground we described in February: more than times tables, less than a full JMO question before breakfast.
Exact Science builds preparation as a maths education lab. problems.cc is where practice lives. The app is the daily front door.
Download Problems.cc on the App Store, or play today’s three puzzles at problems.cc/games.