40 Days

Build consistency with daily check-ins, growing milestones, and private habit tracking.

Watch 40 Days

Watch how daily check-ins, streaks, and growing milestones come together in 40 Days.

Build consistency, one day at a time.

40 Days gives you a focused way to build a habit without turning habit tracking into another task to manage. Choose something that matters, show up today, and watch your progress grow over 40 days. Simple daily check-ins, clear progress, and meaningful milestones keep the focus where it belongs: on your habit.

One day at a time

Create a habit with a name, personal emoji, optional description, and optional daily reminder. Mark today complete or leave it in progress. Past incomplete days appear as missed, giving you an honest picture of your routine.

A clear 40-day gauge keeps your progress visible. Missing a day breaks your current streak, but your history, earned milestones, and all-time best streak remain. Complete the next day to begin a new streak and keep moving forward.

Grow through three milestones

Your habit changes as your consistency grows:

Sprout

7 consecutive days. The routine has started to take root.

Rooted

21 consecutive days. Consistency is becoming stronger.

Flourishing

40 consecutive days. You completed the full journey.

Compare the progress of your own habits through milestone leaderboards, and revisit milestones you earned along the way on your personal timeline.

Every person and habit is different. The 40-day journey provides a practical structure for showing up consistently—it is not a promise that every habit becomes automatic on the same schedule.

Everyday tools, with room to breathe

Track daily completions and view their recorded completion times
Follow current and best streaks with a visual 40-day gauge
Review your calendar, history, completion rates, and trends
Set an optional daily reminder for each habit
Check in quickly from home-screen widgets
Celebrate the 7-day, 21-day, and 40-day growth stages
Compare your habits through milestone leaderboards
Revisit earned milestones on your personal timeline
Archive habits without losing their history or progress
Export and import manual backups whenever you choose
Protect access to the app with your device credential or biometrics
Choose light, dark, or system theme
Adjust text size and choose the first day of the week

What’s new

Google Play listing updated · October 6, 2026

Start free on Google Play: Track up to 2 active habits and discover 10 achievement badges. A one-time purchase unlocks unlimited active habits and all 40 badges. Amazon remains paid upfront with everything included.

See when you checked in: View recorded completion times for each completed day.

Explore your achievements: Weekend achievements now follow your region’s weekend days. Browse all 40 badges, with 10 available free on Google Play and the full collection available to unlock.

Discover 40 achievement badges

There is more to progress than a perfect streak.

Discover 40 illustrated badges that recognize consistency, honest misses, determined comebacks, exploration, and unexpected moments along the way.

Google Play includes 10 achievement badges to discover for free. A one-time purchase unlocks access to all 40; earning them still depends on their goals. The paid Amazon edition includes the full collection.

Each locked badge offers a clue. Follow the hint, try something new, and discover what unlocks it.

Some come naturally. Others take patience.

Can you find all 40?

Choose your edition.

Google Play starts free with up to 2 active habits and 10 achievement badges. A single one-time purchase unlocks unlimited active habits and all 40 badges. Widgets and other features are available in the free edition. The Amazon edition is paid upfront and includes every feature and all 40 badges, with no in-app purchases. Neither edition has ads or subscriptions.

Whether you want to read, study, write, exercise, or practice a skill, 40 Days keeps your progress visible and your next step simple.

Privacy by design

No account is required. Your habit data is stored locally on your device, and the app includes no ads or analytics. You control your backups. Export a password-encrypted backup and restore it when needed. Automatic backup and device transfer are disabled, so save a backup before changing devices. Encrypted backups use a separate password. Optional plain JSON exports are unencrypted and are not protected by app lock.

Read the privacy policy

Website visits and support emails are handled separately. Marketplaces and operating systems may process information independently under their own policies.

Common questions

Can I use it offline?

Yes. Habit tracking and your records stay on your device; no Soondouq Labs account is required. Google Play purchases and ownership checks require store connectivity.

What does the purchase include?

Google Play starts free with 2 active habits and 10 badges. A one-time purchase unlocks unlimited active habits and all 40 badges. Amazon is paid upfront with every feature and all 40 badges included, and no in-app purchases. Neither edition has ads or subscriptions.

How do I move my data to another device?

Export a manual backup, then import it on your new device. Choose password encryption or unencrypted JSON. Automatic app backup and device transfer are disabled; keep your backup and encryption password safe.

What device do I need?

The Android app requires Android 7.0 or later. Check the marketplace listing for compatibility with your device.

Does App lock encrypt my records?

No. App lock uses device authentication to control access. With App lock enabled, privacy settings let you hide habit details in widgets and notifications. Exported files need their own protection.

More help → · Privacy policy →

Start with one day.

Stay consistent. See what can flourish in forty.