Kaizen Timer · Android 8.0+ · Coming soon to Play Store

Hand the phone.
Walk away.

Set a timer, hand your phone to your child. When time runs out, it locks — only your PIN unlocks it. No sneaky swipes, no app switching, no pretending they didn't hear the alarm. Built for parents who want genuine control without the tech complexity.

Download APK How it works

Free: up to 9 min / session Pro: $11 lifetime Zero ads, zero tracking Android 8.0+

9 min

Free per session

$11

Lifetime Pro

Ads & trackers

Android 8+

Supported

In 20 seconds

See Kaizen Timer in action

Set the time. Hand the phone. When time runs out, it locks — only your PIN unlocks it.

How it works

Three screens. Three seconds to set up.

Set the time. Hand the phone. When time's up, it locks. That's the whole product.

Setup screen with time pickers and mute toggle

Timer running with large countdown display

Step 1 · 3 seconds

Set the time

Pick hours (0–23) and minutes (0–59). Optionally toggle “Mute media on timeout”. Hit Start.

Step 2 · however long

Hand over the phone

Your child watches, plays, reads — normally. Timer runs in the background. Warning alerts at 3 minutes and 45 seconds remaining.

Step 3 · automatic

Time's up. It locks.

Full-screen overlay covers everything. “TIME IS UP!” Only the parent's PIN unlocks it. Media audio auto-mutes.

The lock

No bypass. No “just one more minute.”

When time expires, Kaizen Timer drops a system-level overlay on top of everything. Android's SYSTEM_ALERT_WINDOW permission + foreground service keeps it there. Kids can’t swipe it away, can’t switch apps, can’t restart the phone out of it. Only your PIN (or biometric, if you set one) unlocks it.

Full-screen overlay drawn over every other app
Survives app-kill, recent-apps swipe, and most reboot attempts
PIN protection with biometric unlock option
Default PIN 1234 on first install — change immediately

SOS extend · Once per session

Kindness built into the lock.

Sometimes a kid is 30 seconds from finishing their level. The lock screen offers an SOS button: +2 minutes, one time per session. Once used, it's gone until the next timer. Prevents both harshness (always locked exactly when time ends) and abuse (unlimited extensions).

One 2-minute extension per session
Requested by child — no parent intervention needed
Automatically greyed out once used
Reset next time you start a new timer

All features

Small app. Thoughtful details.

PIN lock

4–6 digit PIN you set yourself. Default is 1234 — change it immediately. Forgot it? Reinstall (doesn't lose stats).

Biometric unlock

Optional. Unlock via fingerprint or face. Faster than entering the PIN for trusted adults. Disabled by default.

Time warnings

Two audible alerts — at 3 minutes and 45 seconds remaining — so your kid gets a heads-up to wrap up what they’re doing.

Mute media on timeout

Optional toggle. Silences music, videos, and games when time expires — but leaves ringtones and alarms alone.

Recent presets

Your last 3 timer setups appear as one-tap presets. Recurring “15 min with mute” is one tap away.

Usage stats

Sessions this week, total session count, total minutes. Stored locally — doesn't leave your device.

Background-safe

Foreground service with wake-lock. Timer keeps running if you switch apps, lock the screen, or kill the Timer app from recents.

Zero data collection

No analytics, no crash reporters, no cloud sync. Stats stay on the device. Nothing about your kid leaves your phone.

Shareable

One tap to share the app with another parent via WhatsApp, SMS, or email. Builds community around the tool.

Pricing

Free to try. $11 lifetime to go unlimited.

Free tier has a 9-minute cap per session — enough to see if it works for your kid. Pro is one-time, no subscription.

Free

forever

Up to 9 minutes per session
PIN lock & biometric unlock
SOS extend (+2 min once)
Time warnings (3 min & 45 sec)
Mute media on timeout
Usage stats
Sessions beyond 9 min

Download APK

Recommended

Pro

$11

one-time · lifetime

Everything in Free
Unlimited duration (up to 23 hrs)
No nag banners
Priority email support
All future updates
Transferable to another device

Get Pro — $11 Lifetime

Up to 50% off

Doing something good? We’d love to help.

If you’re a student, running a non-profit, working for a cause, or making a positive impact on people, the planet, or the climate in any way — we’d love to play our small part. Send us a short note about what you do, and we’ll offer you up to 50% off any Kaizen license. Because we also want to give back.

Students Non-profits Climate & cause work Positive impact

Email [email protected]

No paperwork, no forms — just a short note about what you do. We review every request personally.

FAQ

Parents ask

For young kids — no. The lock uses Android’s system-level overlay and a foreground service. Even if your child swipes the app out of recents, the service knows exactly how much time remains and the lock still appears at zero. This app is designed for small children, not tech-savvy teenagers who might find creative workarounds.

They can try — but it won’t help. The foreground service tracks remaining time independently. Swiping the app out of recents, going to the home screen, opening other apps — none of that stops the timer. When time hits zero, the lock screen appears regardless.

Kaizen Timer handles this. When the lock screen appears, media audio (YouTube, games, music) is automatically muted. The lock isn’t just visual — it silences the content too, so there’s no point listening through the lock.

During an active lock, Android requires dismissing the lock screen before allowing uninstall — which needs your PIN. Outside of lock, a young child typically doesn’t know how to uninstall apps. Remember, this is built for small kids, not teenagers.

The timer stops. Kaizen Timer does not auto-launch when the phone restarts, so the session ends. Your PIN is still saved — you’ll just need to start a new timer next time. This app is designed for young children during supervised handovers, not for unattended all-day enforcement.

Not yet — Kaizen Timer is Android-only. iOS doesn’t offer system-level overlay permissions, so a lock-screen-over-any-app behaviour isn’t technically possible on iPhone or iPad.

No. Zero analytics, zero cloud sync, zero tracking of any kind. Usage stats (session count, total time) are stored locally on the device only. We never see any information about who uses the app or how.

Never. Not on Free, not on Pro. We're funded by the $11 Pro purchase — nothing else.

Android 8.0 (Oreo) and later. Covers 99%+ of Android devices currently in use.

Uninstall and reinstall the app. PIN resets to the default 1234; change it immediately after reinstalling.

Know first. Get more.

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