NumLock: Math Screen Lock
NumLock: Math Screen Lock is made and published by Peter Li. AppBrain is an independent app data site and isn't affiliated with Peter Li. The app name, icon, screenshots and description belong to Peter Li and are shown as published on the App Store.
AppBrain's verdict
- Last updated
- April 14, 2026
- Size
- 1.63 MB
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Store listing
By Peter Li, from the App StoreDescription by Peter Li Written by the developer, not by AppBrain. Click to read.
NumLock turns your screen time into brain time. Before you can open your blocked apps, solve a set of mental math problems. It takes seconds, keeps your mind sharp, and adds just enough friction to break the mindless scrolling habit.
HOW IT WORKS
Choose which apps to block. When you try to open one, NumLock presents math problems you solve on a number pad. Get them all right and your apps unlock for your chosen grace period. Simple, fast, and surprisingly satisfying.
ADAPTIVE DIFFICULTY
NumLock starts easy and gets harder as you improve. The 25-level system tracks your accuracy and speed, automatically adjusting to keep you challenged. Start with basic addition. Work your way up to multi-step equations, percentages, and large multiplication. You'll be amazed how fast your mental math improves.
GRACE PERIODS THAT FIT YOUR LIFE
After solving, your apps stay unlocked for a window you choose — 5 minutes for a quick check, 30 minutes for a balanced session, 1 hour for extended use, or until midnight for a full day off. When time's up, the lock comes back automatically.
STREAKS AND STATS
Build a daily streak by solving at least one session per day. Track your accuracy, average solve time, current level, and total problems solved. Watch yourself get faster and sharper over time. Your best streak is always recorded — can you beat it?
DESIGNED FOR ADULTS
NumLock isn't a parental control. It's a tool for people who want to take back control of their own screen time while training their brain. Think of it as a gym membership for your mind that activates every time you reach for a distraction.
FEATURES
— Block any app on your iPhone
— Mental math challenges on a clean number pad
— 25 levels of adaptive difficulty
— Streak tracking with best-streak records
— Accuracy and speed stats dashboard
— Configurable grace periods (5 min to all day)
— Light and dark mode
— No ads, no data collection, fully private
SUBSCRIPTION
NumLock requires an active subscription to use.
— Monthly: $4.99/month
— Annual: $39.99/year (7-day free trial)
Payment is charged to your Apple ID. Subscriptions auto-renew unless cancelled at least 24 hours before the end of the current period. Manage subscriptions in Settings → Apple ID → Subscriptions.
Terms of Use (EULA): https://apptato.github.io/numlockapp/terms.html
Privacy Policy: https://apptato.github.io/numlockapp/privacy.html
Safety and technology
Found in the app by AppBrain- Price
- Free
- App size
- 1.63 MB
- Content rating
- Everyone
Technologies used by NumLock: Math Screen Lock
Releases
Updates seen on the App Store- Version
- 1.0
- Launched
- April 2026
No changelog data
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About the app and developer
About NumLock: Math Screen Lock
NumLock: Math Screen Lock is a productivity app developed by Peter Li.
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The app has no ratings yet.
App Information
NumLock: Math Screen Lock is freely available from the App Store. The app size is 1.63 MB. The latest version available is 1.0. The last update was on April 14, 2026.
Technical Requirements
The app has a content rating of Everyone. The app has been available on the App Store since April 2026.
Developer information for Peter Li
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