A 90-day challenge tracker with teeth. Sign the contract with your own finger, keep your daily rules, and let a streak engine that never resets to zero carry you to day 90.
Download on theApp StoreLive demo: check the rules, watch the day lock in.
You don't tap "start" — you sign with your finger and stamp it. The commitment feels different because it is different, and your signature is there every time you doubt it.
Grace days auto-cover a weekly slip, a 48-hour rescue saves the rest. Comebacks are part of the system, not a walk of shame back to day one.
From your first check-in to a perfect 90, achievements unlock full-screen with progress bars along the way. None of them are handed out for free.
Completion rate, best runs, rule-by-rule breakdowns, weekly rhythm and more — the numbers to prove day 90 you is not day 1 you.
A one-line journal and a photo log capture the arc as it happens. 120 motivational quote cards keep the tone hard, not cute.
Home-screen and lock-screen widgets show tonight's remaining rules, your streak, and your day count — in your theme. Nine accent themes; unlock more by earning them.
Effective date: August 13, 2026
Winter Arc ("the app") is developed and published by the developer listed on our App Store page. This policy explains what information the app handles and how.
The app requires no account and no sign-in. Your challenge data, check-ins, streaks, journal entries, photos, achievements, and settings are stored locally on your device and are not transmitted to us. Photos you add never leave your device.
The free version shows ads served by Google AdMob. If you grant the iOS tracking permission, AdMob may use your device's advertising identifier to show more relevant ads; if you decline, ads are shown without tracking. See Google's Privacy Policy for details. Winter Arc Pro removes all advertising from the app.
We use Google Firebase Analytics to collect anonymous, aggregated usage data (for example, which screens are used and how often the app crashes). This helps us improve the app and is not used to identify you.
In-app purchases, including the Winter Arc Pro subscription, are processed entirely by Apple. We never see or store your payment information. Subscriptions can be managed or cancelled anytime in your App Store account settings.
The app is a general-audience habit tracker and is not directed at children under 13. We do not knowingly collect personal information from children.
If this policy changes, the updated version will be posted on this page with a new effective date. Questions? Email wuyuping38@gmail.com.
Found a bug, have a feature request, or just want to say hi? Email wuyuping38@gmail.com — screenshots always help.