Protocol66

Build yourself in 66 days

Only for iPhone

Free · In‑App Purchases · Designed for iPhone

iPhone

66 days. 5 habits. Miss a day, start over. The science-backed challenge for building real habits. No excuses. No second chances. Ready to commit? 66 days. 5 habits. Miss a day, start over. Protocol 66 is the science-backed alternative to extreme fitness challenges. Based on habit formation research — not bro science — it takes exactly 66 days to build lasting habits. THE RULES ARE SIMPLE - Pick 5 daily habits - Complete all 5 every day - Miss a day, restart from zero - Rest days are earned, not given WHY 66 DAYS? Research by Phillippa Lally at University College London found it takes an average of 66 days to form automatic habits. Not 21. Not 30. Not 75. THIS ISN'T FOR EVERYONE No streaks to protect you. No lives. No second chances. If you're looking for an app that goes easy on you, this isn't it. Ready to commit? -------------------------------------------------------------------------------- Privacy Policy: https://www.pocketapps.studio/protocol66/privacy Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

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Version 1.0.1 • Late Logging - Forgot to log yesterday? Now you can catch up before your challenge fails • Challenge Failed Card - Clear visibility when challenges end with easy restart options • FAQ Section - Find answers to common questions in Profile • Better Notifications - Stay on track with evening reminders and milestone celebrations • Bug fixes and performance improvements for iOS 26

Version 1.0.1

The developer, Pocket Apps Studio Pte. Ltd., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Linked to You

    The following data may be collected and linked to your identity:

    • Contact Info

  • Data Not Linked to You

    The following data may be collected but it is not linked to your identity:

    • Contact Info
    • Identifiers
    • Usage Data
    • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

Accessibility

The developer has not yet indicated which accessibility features this app supports. Learn More

Information

  • Seller
    • POCKET APPS STUDIO PTE. LTD.
  • Size
    • 36.4 MB
  • Category
    • Productivity
  • Compatibility
    Requires iOS 18.0 or later.
    • iPhone
      Requires iOS 18.0 or later.
    • Mac
      Requires macOS 15.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 2.0 or later.
  • Age Rating
    13+
    • 13+
    • Learn More
    • Frequent
      Contests

      Contains
      Gambling and Contests
  • In-App Purchases
    Yes
    • Pro Version $2.99
    • Pro $19.99
    • Lifetime Access $3.99
    • Learn More
  • Copyright
    • © 2026 Pocket Apps Studio Pte Ltd.
  • Developer Website
  • Privacy Policy

    • More by Pocket Apps Studio Pte. Ltd.