Grinn - Smile Reminder

Science says 10 seconds of smiling can change your mood. Grinn makes it a daily habit — with AI that knows when you're really smiling. Your brain will thank you.

Smiling for 10 seconds triggers real endorphins in your brain. Not metaphorically — a 2022 study across 19 countries with 3,878 participants confirmed it. Grinn turns that science into the simplest wellness habit you'll ever try.

No journaling. No 10-minute meditations. Just 10 seconds and your face.

HOW IT WORKS

Tap the button. A gentle countdown begins. Breathe in, hold, breathe out — the built-in breathing guide keeps you grounded. If you turn on smile detection, the timer only counts while you're genuinely smiling. That's it. One session, once a day, and your brain does the rest.

WHAT THE SCIENCE SAYS

This isn't wishful thinking. Grinn is built on 20+ peer-reviewed studies from journals like Nature Human Behaviour and Psychological Bulletin:

• 10 seconds of intentional smiling activates the facial feedback loop, releasing endorphins and serotonin
• Smiling reduces cortisol (your stress hormone) by up to 25%
• A mega-study across 19 countries confirmed the effect is real and replicable
• Even a "forced" smile triggers the same neurological pathways as a genuine one

Grinn includes a full Science section with every study cited — because you deserve to know why this works, not just that it does.

FEATURES

• Guided smile sessions with a breathing guide and haptic feedback
• AI smile detection — the timer pauses if you stop smiling and resumes when you start again
• Streak tracking with milestones at 3, 7, 14, 21, 30, 50, 75, 100, and 365 days
• Daily quotes to keep you inspired
• Smart reminders that nudge you at the right moments
• Dark mode, accessibility support, and privacy by design

GRINN PRO

Unlock the full experience:

• Unlimited daily sessions (free: 3 per day)
• Smile Journal — auto-captured selfies that build a visual timeline of your smiles, stored privately on your device
• Custom timer duration (10-30 seconds)
• Unlimited reminders with custom notification messages
• Full quote library

BUILT WITH CARE

Your photos never leave your device. Camera access is optional. Animations respect your accessibility settings. We built Grinn to be honest — the app even acknowledges that the research shows real but modest effects. No magic promises, just a small daily habit backed by good science.

Feeling better doesn't have to be complicated. It can start with 10 seconds and a smile.

SUBSCRIPTION INFORMATION

Grinn Pro is an optional auto-renewable subscription that unlocks unlimited sessions, Smile Journal, custom timer, unlimited reminders, and the full quote library.

• Monthly: $0.99/month
• Annual: $9.99/year
• Lifetime: $27.99 (one-time purchase)

Payment will be charged to your Apple ID account at confirmation of purchase. Monthly and Annual subscriptions automatically renew unless canceled at least 24 hours before the end of the current period. You can manage or cancel your subscriptions in your device's Settings > Apple ID > Subscriptions.

Terms of Use: https://www.grinnapp.com/terms Privacy Policy: https://www.grinnapp.com/privacy