Fyshh Aero·FITComing soon
Your daily IMSAFE check, informed by the health data already on your phone.
The FIT app is a free daily self-assessment aid for pilots, in development alongside the FLT app. Each morning, and before a flight, it asks the six IMSAFE questions every pilot already knows and shows, beside each one, what your iPhone and Apple Watch already know: last night's sleep against your usual, overnight heart rate, your last drink against the eight-hour rule, a new medication, the heat at your aerodrome.
Everything it reads, learns and writes stays on your iPhone. No account is needed, nothing goes to iCloud, and nothing is sent to us.
The check
Thirty seconds, six letters, and a declaration that is yours
Illness, Medication, Stress, Alcohol, Fatigue, Eating and emotion: Clear, Caution or Not today for each, then your own declaration for the day: Go, Caution or Stand down. The declaration is the record; the app informs it and never makes it for you.
- Morning, and before a flight. A morning check at the time you choose, a pre-flight check on demand, and an evening check if you want one. Each takes less time than the walk-around.
- On the wrist. Apple Watch complications and phone widgets show today's state and take a one-tap report.
- A nudge when something is worth a look. A short night, overnight vitals above your usual, a drink too close to your next flight, a new medication, heat at departure time. Local notifications, with quiet hours, and no more than three a day.
FIT is a self-assessment aid, not a medical device. It never decides whether you are fit to fly. Under CASR 91.520 and FAR 91.17 that remains the pilot's responsibility, and the app says so on every screen that could be read otherwise.
The signals
What your devices already know about each letter
With your permission, and only for the categories you choose, the FIT app reads what Apple Health already holds from your watch, sleep tracker, scales, blood-pressure cuff and nutrition apps, and shows the signals that matter for each letter against your own usual values. Every signal is estimated and labelled as such.
Illness
Overnight resting heart rate, heart-rate variability, respiratory rate, wrist temperature and blood oxygen against your own baseline, and the symptoms you log in Health.
Medication
A new medication or a changed dose from the medications you record in the Health app, with a reminder that CASA advises a ground trial and DAME clearance for a new medication. The app never classifies a medication; it only notices a change.
Stress and emotion
Your State of Mind entries and mindful minutes, and the heart-rate and sleep patterns that tend to go with a hard week, against your own history.
Alcohol
Your last logged drink against an eight-hour minimum you can lengthen but never shorten. The app does not estimate blood alcohol.
Fatigue
Last night's sleep against your usual, how long you will have been awake at departure, and the sleep debt of the last few days.
Eating and environment
Meals, water and caffeine logged in Health, the heat index at your aerodrome from Apple Weather, and, if you connect them through Apple Home, the temperature, humidity and air quality of the room you slept in.
Learning
After fourteen days it starts each morning with an estimate, in your own terms
For the first fourteen days and ten check-ins the app only listens: your answers against your signals. Then it starts each day with an estimate per letter and the reasons in plain words, calibrated against your own personal data and shared with no one. The estimate is a suggestion to confirm or override; your answers keep teaching it.
- Written on your phone. On a supported iPhone the morning summary and the weekly review are written by the on-device model of Apple Intelligence. Nothing leaves your phone to produce them, and every generated text is marked as generated on your iPhone.
- Other iPhones see the same screens with templated text in place of the generated summary. Nothing advertised is missing.
- Your model, your phone. The personal baselines and the model fitted to your own answers live in the app's storage on the phone. You can export all of it, move it to a new phone in an encrypted archive, or delete it in Settings.
The estimates are calibrated against your own personal data, not shared with anyone, and still being refined. They are labelled estimated in the app, and the declaration you make is the only record kept.
On your phone, nowhere else
Health data is processed on the device and never synced
The FIT app is built so that the question "where does my health data go" has a one-word answer: nowhere.
Processed on the iPhone
Every health value the app reads, every signal it derives and every baseline it learns is computed and kept on your iPhone. The only health data in the Fyshh Aero ecosystem that is handled differently is the heart rate the FLT app logs during a flight, if you turn that on there, which travels with that flight's record under FLT's own rules.
Not synced to us
No health value, no number from your health data and nothing per letter is ever sent to Fyshh Aero. Without an account the app makes one kind of network request: your coordinates to Apple Weather for local conditions, with no account or identifier attached.
Not synced to iCloud
The app does not use iCloud. Your Apple Watch holds your latest check-in state for its complications and nothing else. Moving to a new phone is done with an encrypted archive you export and import yourself.
Predictions made on the device
The estimates and the written summaries are generated on your phone: the personal model from your own answers, and the words from the on-device model of Apple Intelligence on a supported iPhone. Nothing is sent to Apple or to us to produce them.
Only the outcome, only if you opt in
With a Fyshh Aero account and the Standard subscription, and only when you turn on "Attach my IMSAFE check to my flights", the app sends each check-in's outcome, Go, Caution or Stand down, with its time and kind, to your Fyshh Aero profile. We attach it to the flight you recorded with FLT in the following hours and show it in your logbook. Nothing else leaves the phone.
Shared with a school only by a second switch
If you also turn on "Share my IMSAFE check with my schools", the instructors and school staff who can already see a shared flight see its outcome and time beside it. Nothing more, and private flights never carry it.
The privacy policy sets this out in full, including what the app reads, what it keeps and for how long.
With FLT and the portal
Complete on its own, and part of the record if you want it to be
A share of FIT users will never fly with FLT, and the app is complete without it. With a Fyshh Aero account and the Standard subscription, the two work together:
- Your check beside your flight. Each check's outcome and time are attached to the flight you record with FLT and shown in your logbook in the app and on the web portal.
- A note at flight start. Starting a flight in FLT shows a one-line note on the phone and the watch if today's check is missing or anything other than Go with every letter clear.
- Your results on Go and Caution days. Your own landing and turn scores compared across the days you declared Go and the days you declared Caution.
- Your school, if you choose. The outcome and time on a shared flight, visible to the instructors who already see that flight.
iPhone with iOS 26 or later. Generated summaries need an iPhone that supports Apple Intelligence, iPhone 15 Pro and later, with Apple Intelligence turned on; other iPhones show the same screens with templated text. Apple Watch with watchOS 26 is optional. There is no iPad version.
Coming soon
Hear when FIT is on the App Store
The FIT app is in build and test now. Leave your e-mail and we will tell you when it ships, and nothing else.
The FIT app will be a free download, usable with no Fyshh Aero account at all. It is a safety offering to the community first and an entry to the ecosystem second.