Some days are foggy.
Find out why.
FoggyBrain is a gentle iPhone app that connects your brain fog to sleep, stress, food, and weather — and shows you what actually helps.
Free to use. No account. Your data stays yours.
Three small habits. One clearer head.
1
Log in two taps
Rate your fog when you think of it — from the app, a widget, or your Lock Screen. It takes seconds, on purpose.
2
Let patterns emerge
FoggyBrain quietly lines your ratings up against sleep, stress, sugar, exercise, cycle, and even the weather.
3
See what helps
After a couple of weeks, your triggers stop being a mystery. Bring the report to your doctor, or just to yourself.
Why this app exists
Built by someone who lived in the fog
FoggyBrain wasn't designed in a boardroom. It was built during a long COVID recovery, by someone who needed it — and couldn't find it.
Read our story
Now in private beta
Get early access
We're testing with a small group before the App Store launch. Join the list and get a link to test the app for free.
Understand your fog
All articles
Understanding
Thyroid and brain fog
Why an underactive or overactive thyroid can cloud your thinking, and whether it's worth getting tested
5 min read
Lifestyle
Screen time and brain fog
Why hours of scrolling and switching tabs leave your mind feeling scattered and tired
5 min read
Lifestyle
Dehydration and brain fog
How even mild fluid loss slows your thinking, and how to actually fix it
4 min read
Private by design
No account. No ads. No trackers. Your data lives on your iPhone and in your own iCloud — never on our servers, because we don't have any. Even the AI insights run entirely on your device.
Read the privacy policy