Simple & fast.
Smart AI coaching, beautiful design and super easy to use.
Free
In-App Purchases
Details
About
This app uses AI to provide personalized daily audio coaching and articles to help you build lasting habits over 66 days. It offers a chat coach for support and tracks your progress with visual timelines and reminders.
✓Personalized daily AI articles
✓Narrated daily audio sessions
✓AI chat coach for support
✓Visual 66-day timeline
✓Streak counter
✓Customizable habit creation
✓Daily reminders
Show original description
What's New in 66
1.1
July 14, 2026
Fixes and Improvements.
Subscription plans
Monthly Subscription
Monthly subscription for 66 Pro
$9.991 Month
User reviews
Developer apps
FAQ
What is the science behind 66?
66 is based on research from University College London, which found that the average time to form a habit is 66 days, not the commonly cited 21 days. The app emphasizes consistency over intensity to make behaviors automatic.
What kind of habits can I track with 66?
You can choose from 22 built-in habits across categories like Mindfulness, Fitness, Nutrition, Productivity, and Sleep. You can also create fully custom habits tailored to your specific goals.
Does 66 have ads?
No, 66 is ad-free. The app focuses on providing a seamless user experience without interruptions from advertisements.
How does the AI chat coach in 66 work?
The AI chat coach is available 24/7 to answer your questions, help you overcome challenges, and provide motivation. It stays in context with your habit-building journey.
What are the subscription options for 66 Pro?
66 Pro offers monthly ($9.99), six-month ($49.99 with a 3-day free trial), and yearly ($95.99 with a 7-day free trial) subscription plans. These unlock all features, including AI articles, audio sessions, and the chat coach.
Can I cancel my 66 Pro subscription?
Yes, you can manage or cancel your subscription anytime in your App Store account settings. Subscriptions automatically renew unless canceled at least 24 hours before the end of the current period.
What devices is 66 available on?
Currently, 66 is supported on iPhone. The app is designed to provide a consistent experience across Apple's mobile devices.
How often is 66 updated?
The app was last updated on July 14, 2026, indicating regular maintenance and potential feature additions. This suggests a commitment to improving the user experience and reliability.