Duo: 75 Hard Challenge
Your challenge, together
Free · Designed for iPad
Follow through on a challenge with someone who can see your progress. Duo keeps your shared plans and today’s tasks in one place.
TOGETHER OR ON YOUR OWN
Start a personal challenge or invite a partner through iCloud. See each other’s check-ins and progress. Share an invitation through WhatsApp, Messages or email. Once your partner accepts your shared plan, the challenge starts for both of you on the same day.
TASKS THAT MATCH YOUR PLANS
Choose the length and tasks. Check off a habit, track an amount or add a personal progress photo. The 75 Hard template includes tasks for two workouts, water, reading, diet and a photo. You confirm workouts yourself; version 1 does not record workouts.
SEE YOUR PROGRESS
Review your days, tasks and streak. Home Screen and Lock Screen widgets show how things are going. Send your partner encouragement or an invitation to walk.
NOTIFICATIONS YOU CONTROL
Enable reminders and partner notifications and choose your quiet hours. Partner notifications appear after changes arrive through iCloud; timing depends on iOS and your connection.
PRIVACY
No separate Duo account is needed. Shared challenges and sync require an Apple account with iCloud. You share challenge rules and progress with your partner. Your progress photo stays within the app on your device; your partner only sees whether the photo task is complete. Duo has no ads or analytics.
APPLE HEALTH
Optionally let Duo read your steps from Apple Health after granting permission. Version 1 does not write data to Health.
Available in English, Dutch, German, French, Spanish, Italian, Portuguese, Japanese, Korean and Chinese. Duo is an independent app and is not affiliated with the creators of 75 Hard.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Improved loading of shared challenge invitations, reopening invitation links, and synchronization when a challenge starts for both participants.
The developer, Ruud Slagers, 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 Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Ruud Slagers
- Size
- 12.2 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - iPad
Requires iPadOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later.
- iPhone
- Languages
English and 9 more
- English, Dutch, French, German, Italian, Japanese, Korean, Portuguese, Simplified Chinese, Spanish
- Age Rating
13+
- 13+
- Infrequent
Alcohol, Tobacco, Drug Use or References
Contains
Health or Wellness Topics
- Copyright
- © 2026 Ruud Slagers