CronTab
Free Cron Expression Builder & Explainer for Android
Build cron expressions visually, paste one to get a plain-English explanation, preview the next 10 run times, and save your favorites. A must-have pocket reference for anyone who works with scheduled tasks.
Features
Visual Builder
Build expressions with mode selectors (Every, Specific, Range, Step) for each of the 5 cron fields. Live preview updates as you change settings.
Plain English Explainer
Paste any cron expression and get a human-readable description. "0 9-17 * * 1-5" becomes "Every hour from 9 AM to 5 PM, Monday through Friday."
Next Run Preview
See the next 10 execution times for any expression. Know exactly when your job will fire.
Saved Expressions
Save frequently used expressions with custom labels. Tap to copy, always available offline.
Cheat Sheet
15 common patterns from "every minute" to "weekdays 9-5." One-tap copy to clipboard.
Validation
Full cron syntax validation with clear error messages. Supports lists, ranges, steps, and named values (MON, JAN, etc.).
Dark Theme
Beautiful Catppuccin Mocha dark theme. Perfect for server room lighting conditions.
Offline & Lightweight
Everything runs locally — no internet needed for building or explaining expressions. Tiny APK.
No External Libs
Custom-built cron engine with efficient skip-ahead scheduling. Parses and calculates instantly.
Common Cron Patterns
| Expression | Description |
|---|---|
| * * * * * | Every minute |
| */5 * * * * | Every 5 minutes |
| 0 * * * * | Every hour |
| 0 0 * * * | Daily at midnight |
| 0 6 * * * | Daily at 6:00 AM |
| 0 0 * * 1 | Weekly on Monday |
| 0 0 1 * * | Monthly on the 1st |
| 0 9-17 * * 1-5 | Weekdays 9 AM - 5 PM (hourly) |
Download
Version: 1.0.0
Size: ~5 MB
Requires: Android 8.0+ (API 26)
Price: Free (ad-supported)
Google Play listing coming soon.
Direct APK download:
Download APKSecurity & Privacy
- ✓ No account required — works completely offline
- ✓ No data collected, no analytics, no tracking
- ✓ Saved expressions stored locally on your device only
- ✓ No network requests except for ads
- ✓ ProGuard/R8 obfuscation in release builds
- ✓ Android backup disabled