Hangarfolio

Hangarfolio Privacy Policy

Last updated: 2026-09-27

Mountain Buffalo Limited (“Mountain Buffalo”, “we”, “us”) makes Hangarfolio, an app for tracking an aircraft’s maintenance, flights, squawks and costs, and for sharing an aircraft with its co-owners. This policy explains what Hangarfolio collects, where it goes, and the choices you have.

The short version

  • Without a Hangarfolio account, we don’t receive your aircraft data. It stays on your devices and, if you use iCloud, in your own private iCloud storage, which only you can read.
  • You need an account only to share an aircraft with co-owners or to join one. Then the shared aircraft is stored on our servers so everyone on it sees the same thing.
  • We don’t sell your data, show ads, or track you across apps or websites. Hangarfolio has no advertising or analytics SDKs.
  • You can delete your account in the app at any time (Account & Sharing → Delete Account).

What Hangarfolio stores and where

On your devices and in your iCloud

Everything you enter for an aircraft only you use: tail number, make, model and engine, meter readings, maintenance items and their history, flights, squawks and their photos, expenses, receipts, and the costs you set. Hangarfolio keeps it on your device and syncs it across your devices through your private iCloud database (Apple CloudKit). Apple’s privacy policy applies to iCloud. Mountain Buffalo can’t access your iCloud data.

On our servers, when you use an account

If you create an account, or sign in to share or join an aircraft, we store:

  • Account details: your name, email address, and optionally a phone number. If you use Sign in with Apple, we receive the email Apple provides, which may be a private relay address, and your name the first time you sign in.
  • Your sign-in: passwords are handled by Amazon Cognito. We never see or store your password in readable form.
  • Shared aircraft data: everything on a shared aircraft, as listed above, plus bookings on its schedule, group rules, hourly rates, payments between owners, and the ledger that splits costs. Photos and receipts you attach are stored with it.
  • Invites: when you invite someone, we store the name and phone number or email you enter, so the invite can be shown and revoked. The invite message itself is sent from your own device, in Messages or Mail. We don’t send it.
  • Push notifications: a device token, so we can send reminders and updates about shared aircraft to your devices.
  • Subscription status: whether you have an active Hangarfolio subscription, its plan and expiry, and which aircraft it covers. Payments are handled by Apple. We never receive your payment details.
  • Server logs: technical records of requests (time, the kind of request, how long it took, and errors) used to keep the service running. We keep them for up to 3 months.

Meter photos you choose to share

When you log a flight, you can photograph the Hobbs meter, tach or engine display, and Hangarfolio reads it on your device. The photo isn’t sent anywhere for that. If Hangarfolio can’t read a photo, or reads it wrong and you correct it, you can choose to share it to help Hangarfolio learn to read meters like it. This is off unless you turn it on for that photo. When you save the flight, we receive:

  • the photo, re-saved by the app without its location or other camera details;
  • the reading you entered, and the text Hangarfolio found in the photo;
  • which kind of meter it is.

A shared photo isn’t linked to your account, email, aircraft or flight, and it works without an account. To stop abuse, we also keep a random identifier for your app install with it for one day, then delete that identifier. Please frame the meter only, since anything else in the photo is shared too.

What co-owners see

Everyone on a shared aircraft sees its data, including each owner’s name, flights, bookings, squawks, expenses and balances. Co-owners are equal: any owner can invite or remove others.

Signatures on logbook records

When you sign a record in Hangarfolio, such as a VOR check, you confirm with Face ID or your device passcode. That check happens entirely on your device through iOS. Hangarfolio and Mountain Buffalo never receive your face data or passcode. The saved record contains your typed name, the time, and a fingerprint of the record.

What we don’t collect

Hangarfolio doesn’t use your location, contacts, or advertising identifier. Photos you attach are re-saved by the app without their location. The airport lookup is built into the app and works offline.

How we use data

We use the data above only to run Hangarfolio. That means signing you in, syncing and showing shared aircraft to their owners, sending the emails and notifications you’d expect (sign-up codes, password resets, reminders, co-owner activity), checking your subscription, preventing abuse, and fixing problems. We use meter photos you choose to share, and their readings, only to improve how Hangarfolio reads meters, including to train and test models that read them. We don’t use it for advertising or profiling, and we don’t sell or rent it.

Service providers

We use these providers to run Hangarfolio. They process data only on our behalf, or under their own terms where noted:

  • Amazon Web Services (United States, Ohio region): servers, database, file storage, sign-in (Cognito), email (SES) and push delivery (SNS).
  • Machine learning providers: if we use a provider to help train or run a model that reads meters, it receives shared meter photos and readings only to do that for us.
  • Apple: App Store purchases and subscriptions, iCloud, Sign in with Apple, and push notifications. Apple’s privacy policy applies.
  • RevenueCat: confirms and manages App Store subscriptions. It receives an anonymous account identifier and purchase records from Apple, never your payment details.

We may disclose information if the law requires it, or to protect the rights, property or safety of our users or others.

Security

Data is encrypted in transit (HTTPS) and at rest on our servers. Stored files aren’t publicly accessible. No system is perfectly secure, but we limit access to the people and systems that need it.

Keeping and deleting your data

  • Aircraft only you use stay on your devices and in your iCloud until you delete them.
  • Deleting your account in the app removes your name, email, phone, devices, sign-in and subscription record from our servers:
    • Shared aircraft that no one else is on are deleted with everything in them.
    • On aircraft shared with others, your flights and ledger entries stay, so the other owners’ records and balances remain correct. They’re shown as “Former co-owner” without your name.
    • Deletion from our database backups follows as they expire, within 14 days.
  • Stopping sharing an aircraft you’re the only owner of deletes its copy from our servers. It moves back to your iCloud.
  • Shared meter photos are kept for as long as they help improve meter reading. Because they aren’t linked to you, we can’t find a particular photo to delete it later. Don’t share a photo you’d want back.
  • Your App Store subscription isn’t cancelled by deleting your account. Cancel it in your Apple account settings.

Your rights

Depending on where you live (for example, under the GDPR or the California Consumer Privacy Act), you may have the right to access, correct, export or delete your personal information, to object to or restrict its processing, and to complain to a data protection authority. You can delete your account in the app. For anything else, email support@mountainbuffalo.com and we’ll respond within 30 days. We don’t sell or share personal information for cross-context behavioral advertising.

If you’re in the EEA or UK: we process account and shared-aircraft data to provide the service you ask for (performance of a contract), server logs for our legitimate interest in keeping Hangarfolio secure and working, and meter photos you choose to share with your consent, given when you turn on sharing for that photo.

Children

Hangarfolio is for adults (18 or older, or the age of majority where you live). It isn’t directed to children, and we don’t knowingly collect their personal information. If you believe a child has given us information, contact us and we’ll delete it.

International users

Our servers are in the United States. By using an account, you understand your information will be processed there.

Changes

We’ll post changes to this policy on this page and update the effective date. If a change is significant, we’ll tell you in the app before it takes effect.

Contact

Mountain Buffalo Limited 1500 N Grant St, Suite #5911 Denver, CO 80203, USA support@mountainbuffalo.com