# Duo: 75 Hard Challenge — Your challenge, together

> Your challenge, together (iPhone/iPad app by Ruud Slagers.)

- Source: https://appshunter.io/ios/app/duo-75-hard-challenge/id6819230205 (this page in markdown: same URL + `.md`)
- Developer: [Ruud Slagers](https://appshunter.io/developer/1873281390)
- Category: Health & Fitness
- Price: Free
- Age rating: 12+
- Requires: iOS 18.0 · 12 MB
- Languages: American English, Dutch, French (France), German (Germany), Italian, Japanese, Korean, Brazilian Portuguese, Chinese (Simplified, China), European Spanish
- Released: 2026-10-14
- Data updated: 2026-10-16

## What is Duo?

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.

## Is Duo safe?

Not enough ratings yet to assess Duo.

## Is Duo legit?

Duo: 75 Hard Challenge has limited verification signals. The AppsHunter Legitimacy Score for Duo is 58 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 2 releases)

### 1.1.1 — 2026-10-15

Improved loading of shared challenge invitations, reopening invitation links, and synchronization when a challenge starts for both participants.

### 1.0 — 2026-10-14

No release notes.

## More apps by Ruud Slagers

- [Wandertales: Travel Stories](https://appshunter.io/ios/app/wandertales-travel-stories/id6758516367)

All apps by Ruud Slagers: https://appshunter.io/developer/1873281390

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-16.*