Zetapro
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Works on any computer, tablet or phone. Nothing to install.
Open ZetaproGet faster at mental maths.
A Zetamac-style speed game and an Optiver-style “80 in 8”, with stats that show exactly which kinds of problems slow you down, and drills that fix them.
Free · no ads · sign-in optional
Why I built it
Zetamac is great for building speed, but at the end of a round all it gives you is one number. I wanted to know why my score was stuck: which kinds of problems were costing me time, and which mistakes I kept making.
So Zetapro times every answer, sorts it by type, and turns your slowest types and most-missed problems into targeted drills, so practice goes where it helps most. Then I added what I wanted for interview prep: an Optiver-style 80 in 8, goals to hit consistently, and sync so my phone and computer stay in step.
Three ways to use it
On your phone
Open the app, then add it to your home screen. It opens full-screen and works offline.
- iPhone: Safari → Share → Add to Home Screen
- Android: Chrome → ⋮ → Install app
Windows app
A standalone desktop app. Download, unzip anywhere, and run Zetapro.exe.
Windows may warn that the publisher is unknown, because the app isn't code-signed. Click More info → Run anyway.
On a Mac? Use the browser version. In Chrome you can also install it as an app from the address bar.
What's inside
Classic Zetamac
Same rules and defaults: 2 minutes, answers accepted the instant they're right.
Find your weak spots
Every answer is timed and sorted by type: carries, borrows, each times table, 2-digit products.
Targeted drills
Smart drills built from your slowest types, plus the exact problems you keep missing, with pace tracked per minute.
80 in 8
80 multiple-choice questions in 8 minutes: decimals, fractions, missing numbers. Net scoring.
Goals and progress
Set a target score and see how often you hit it, and how each round compares with your recent average.
Sign in and sync
Optional: sign in with Google or email and your games follow you across phone, tablet and computer.
Made for phones
A built-in number pad, tabs within thumb reach, and it works offline once added to your home screen.
Undo and backups
Undo a delete, bring back earlier synced versions, or export everything to a file.
Built for focus
An optional 3-2-1 start, a red clock for the final seconds, and nothing else on screen.
About
Free, no strings
No ads and no tracking: the site uses no analytics. Signing in is optional; everything works without an account.
Your data stays yours
Games are saved on your device. If you sign in, they sync to your own private account, which only you can read.
Independent
A personal practice project. Found a bug or have an idea? Open an issue on GitHub.