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30-day challenges

A 30-day challenge app you do with friends

By the DuoShare team · Updated November 2026 · Leer en español

A 30-day challenge app gives you a daily check-in and a finish line 30 days out. DuoShare runs 30-day challenges you start with one link: friends join, everyone checks in each day, and you all see who is done. Groups of up to 4 are free.

Why 30 days works

Thirty days is long enough to notice a real change and short enough to commit to. It is also a natural first milestone on the way to a habit that sticks, which research puts closer to 66 days. Many people run a 30-day challenge, then roll it into a 66-day one.

30-day challenge ideas

Set a daily target

Challenges can have a daily target: 20 pages, 30 minutes, 5 kilometers, 8 glasses. You check in when you hit it, and everyone in the challenge sees it.

DuoShare at a glance

What it is
An accountability habit tracker for iPhone: you and your friends check off goals and see when each other is done.
Price
Free. Goals, friends, streaks, reminders, the widget and challenges with up to 4 people cost nothing.
DuoShare Pro
Optional: groups and challenges of 5 to 10 people. $29.99 once, or $4.99 a month.
Platform
iPhone (iOS). No Android or web app yet.
Challenges
7, 30 or 66 days, with one friend or a group, joined with one link.
Streaks
Your streak grows every day you check off a goal. Mark a goal N/A once a week without breaking it.
Sharing
Every milestone becomes a card you can post to Instagram, Messages or anywhere.
Privacy
Goals are private until you share them with friends you choose. Nothing is public. Your journal is never shared.
Languages
English and Spanish.
Made by
SearchWrite LLC, United States.

Start in under a minute

  1. Get DuoShare free on the App Store and sign up with your phone number.
  2. Add one to three small goals. Small sticks.
  3. Send a friend your invite link. Your streak starts with your first check-in.
Get DuoShare, free on iPhone

iPhone · Free · No ads

Questions

What is a good 30-day challenge to do with friends?

Something everyone can do daily without equipment: a step goal, reading 10 pages, no phone in bed, or drinking water before coffee.

Is there a free 30-day challenge app?

Yes. DuoShare is free for challenges with up to 4 people.

Can we do different goals in one challenge?

A challenge is one shared habit. Each friend can also have personal goals alongside it.

What happens after 30 days?

Everyone gets a finish card to share, and you can start a 66-day challenge to make it stick.

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