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 storyUnderstand your fog
All articlesUnderstanding
What is brain fog?
Understanding the symptoms, causes, and what's happening in your brain
4 min read
Lifestyle
Sleep and cognitive clarity
Why sleep is the single most powerful lever for reducing brain fog
5 min read
Lifestyle
Nutrition and the foggy brain
How blood sugar, inflammation, and gut health shape your cognitive clarity
5 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