Privacy & Security

Sky Matrix is built to keep your data on your device and to use outside services only where a feature genuinely needs them. This page explains what stays local, what leaves the device, the third parties involved, and how to verify the Android apps before installing them.

This page covers three separate products. Most of it describes Sky Matrix, the flight-briefing service. Matrix Clock and Matrix Budget are separate apps with much shorter answers of their own; each has its own section immediately below, and nothing described elsewhere on this page applies to them.

Matrix Clock (Android app, on Google Play)

Matrix Clock collects no personal data. None at all. There is no account, no sign-in, no analytics, no crash reporting, no advertising and no tracking of any kind. It is a separate app from the Sky Matrix briefing service, and none of the licensing, AI, lookup, payment, waypoint-sharing or flight-sync behaviour described elsewhere on this page applies to Matrix Clock.

• Your alarms, rest plans and times stay on your device. They are held in the app's own storage and are never uploaded to us. Clearing the app's data removes them.
• The only thing the app ever sends is a request asking what the time is. It checks the clock against public internet time servers — time.google.com, pool.ntp.org and time.cloudflare.com — because your phone's clock drifts and every alarm depends on it. Those requests contain no information about you. As with any internet request, your device's IP address is visible to the server it contacts; we never receive it and never store it.
• If you have Android's backup switched on, your alarms are included in it. That backup goes to your own Google account and is governed by Google's terms, not ours — we have no access to it. You can turn it off in your device's backup settings, and the app will keep working exactly as before.
• The position on the Times tab works out sunset, sunrise and prayer times, and it never leaves the device. You can type it, or tap My position, which asks Android for one location fix at that moment, while the app is open on that screen. That button is the only thing that ever reads your location: there's no background location, no tracking, and the fix isn't saved or sent anywhere. Android asks your permission the first time, and the app works fully without it if you'd rather type the position.

Because nothing is collected, there is nothing for you to request a copy of and nothing for us to delete. Uninstalling the app removes everything it held.

Matrix Budget (Android app)

We don't receive any of your financial data. Matrix Budget keeps your accounts, cards, loans, budgets and every entry in the app's own storage on your phone. There's no analytics, no advertising and no crash reporting, and none of your figures is ever sent to us, so the only copies of them are the ones on your phone, in the backups you choose to make, and (direct-download version only, if you set it up) in your own Firebase project. The Google Play version has no account.

• Google Play subscription check. The Google Play version is free to try for 14 days and then a subscription bought through Google Play. To confirm a subscription, the app sends two things to Sky Matrix's licence service: a random install ID the app made up when it was installed (not your Google account, phone number or device serial), and the Google Play purchase token for your subscription. The service asks Google whether that subscription is active and returns a signed licence to the app. We keep the install IDs linked to a purchase token (at most three) so one subscription can't be shared beyond its limit; we never receive your name, email, card or any of your budget. Payment is handled entirely by Google Play. To have this record deleted, email support@skymatrix.biz.
• Bank notifications are read on the phone and stay there. If you give Matrix Budget notification access, it looks at notifications from bank and payment apps, picks out the amount, the merchant and the card, and shows you an entry to confirm. The notification text isn't uploaded. Messages it couldn't read are kept on the phone, with long digit runs masked, so you can re-scan or delete them later. The version sold directly from skymatrix.biz can also read bank SMS the same way; the Google Play version has no SMS permission at all.
• Cloud sync exists only in the direct-download version, and runs on your own Firebase project, not ours. The Google Play version has no cloud sync and never connects to Firebase. In the direct-download version, to sync two devices you create a free Firebase project in your own Google account and paste its settings into the app; you then sign in with an email and password you choose. Your ledger is stored there under your sign-in, and we have no access to that project. Firebase is a Google service and its terms apply to it.
• Exchange rates come from a public rates service (cdn.jsdelivr.net, falling back to currency-api.pages.dev). The request asks for the day's rates and carries nothing about you.
• Android backup. If backup is on, your budget is included in it so a new phone can pick it up; that backup goes to your own Google account. The raw notification and SMS queues are excluded from backup and device transfer.
• The direct-download version checks skymatrix.biz for a newer version. That request sends nothing about you. The Google Play version doesn't do this; Google Play handles its updates.

Deleting your data. Everything on the phone goes when you uninstall the app or use Settings → Reset everything. The Google Play version creates no account; the only record we hold for it is the subscription check described above, which we delete on request at support@skymatrix.biz. If you used cloud sync in the direct-download version, the sync account and the ledger stored with it are in your own Firebase project, and you delete them from your Firebase console: Delete your Matrix Budget sync account.

What stays on your device — Sky Matrix briefing service

Your flight data lives only in your browser/app storage on your device:

• The OFP text you load and every field you type (times, weights, crew, notes).
• Your PIN, stored only as a one-way hash, and your biometric enrolment, which stays in your device's secure hardware and is never sent to us.
• Documents you add to the in-app DOCS store and your saved announcements.
• GPS positions for take-off and landing times. When you arm GPS, the app reads your position to stamp blocks-off, take-off and landing. In the Android app (v1.10 and later) a foreground service keeps recording while the app is in the background or the screen is off, with a notification saying so and a Stop button; the positions are held on the phone only until the app next opens, used for those times, and discarded. They are never uploaded. Disarming GPS stops it.
• Notifications. The Android app can show a reminder (a check, a wind update, a turbulence alert, a missed time) as a phone notification when it is not in front. Notifications are made on the phone; nothing is sent to us to produce them. You can switch them off in Android settings.
• Your Sky Matrix Academy progress (INIT → Learn): the episodes and lessons you finish, your quiz answers and certificates are kept in this browser. There is no Academy account; the videos are fetched from skymatrix.biz like any other page.

None of this is uploaded to any Sky Matrix server. Clearing the app's data removes it.

What leaves the device, and why

A few features need the internet and send the minimum data required:

• Licensing & trials, your Device ID and email are sent to our licensing service to issue or validate an access code. INIT → Settings lists the devices on your account and the email they are signed in with; that list is shown only to devices signed in with the same email.
• AI OFP reading & announcement fill, when you tap these, the relevant OFP text or announcement template is sent to our service to be processed and returned. It is not used to build a public profile of you.
• Reading the weather charts, only when you tap Read the charts with Sky Matrix AI on the Route sheet: the chart pages of your flight plan (and only those pages) are sent to our service, which describes the weather on your route by waypoint. The answer is kept on your device with that flight plan.
• Reading a photo, only when you photograph a clearance on the ATC page or a printed announcement in the PA maker: the photo is sent to our service, which returns the text it can read. The image is not kept, and the text stays on your device.
• The route map: your route, FIRs and countries are drawn on the device from data built into the app. Ticking SIGMETs fetches the current worldwide SIGMETs through our service, and the request carries nothing about you or your flight. Ticking Satellite IR loads image tiles directly from NASA’s public GIBS service (gibs.earthdata.nasa.gov); like any web request, your device’s IP address is visible to NASA, and the tiles requested show the part of the world the map is looking at.
• Writing a review on skymatrix.biz: your Device ID and the email your account is registered to are checked against your registration. The email is kept with the review for moderation only and is never shown publicly; the published review shows only the name, position, airline, rating and comment you gave.
• Aircraft, weather & NOTAM lookups, a flight number/registration or airport code is sent to the relevant data provider to fetch results.
• Payments, handled entirely on the checkout provider's site; we never see or store your card details.
• Shared waypoint positions, when your flight plan prints a latitude and longitude beside a waypoint, that waypoint's name and position are contributed to a shared reference database, so pilots whose operator prints no coordinates still get a complete nav log. Only the waypoint name, its position and the name of the FIR it lies in are sent — never your callsign, flight number, date, aircraft registration, route or any crew name. Flight plans hold other crew members' names and roster details, so none of that leaves your device. Your Device ID is not stored beside a position: it is combined with the waypoint name and hashed, so the records cannot be read back as a history of where you have flown. A shared position is available to other pilots straight away; the same place reported again is counted, and a name found in two different places is kept as two entries for the pilot to choose between. You can turn this off at any time in INIT → Settings → Privacy; turning it off stops all sending, and you still receive positions others have contributed.
• Sending a flight to your own second device, only when you press Send this flight under Send to my other device on INIT → Load. Nothing is sent automatically and nothing is polled in the background. What you send is the flight you have open — the parsed flight plan itself, plus the times, nav-log actuals, weights and notes you have entered. It is stored against your account, readable only by devices signed in with your email (the same two the licence allows), and deleted automatically 36 hours later. A flight plan holds other crew members' names and roster details, so if you would rather none of that reach our servers at all, leave the switch in INIT → Settings → Privacy off and use the 6-digit share or a handover file instead, which move the same data device to device — the 6-digit code holds it on our server for at most 15 minutes and deletes it when it is collected; a handover file never touches our server at all.
• The OFP inbox (INIT → Load → OFP inbox). Your account has a private email address of the form ofp-…@skymatrix.biz. Anything you email to it, for example an OFP sent from your flight-planning website or from your airline app’s share sheet, is received by our server: the attached PDF or text flight plan is kept against your account for 36 hours and then deleted automatically, and at most the 12 newest are kept. We keep the file, its name, the email’s subject, the sender’s address and the time it arrived. The rest of the email is not kept, and mail to this address is never forwarded and never read by a person. Only devices signed in with your account email can list or download it. Sky Matrix loads nothing from the inbox until you tap Load. A flight plan holds other crew members’ names and roster details: if you would rather none of that reach our servers, do not email plans to this address, and pick the PDF on the device instead. Anyone who knows the address can send to it, so treat it as private. Change address retires the old one at once.

If your airline runs Flight Control

Some airlines run their own copy of Sky Matrix, called Flight Control, on their own servers. If you open the app from your airline's address, or register your device with your airline, this section applies as well.

• What you enter for your airline goes to your airline, not to us. Flight Acceptance, Post Flight, the PIN or Face ID approvals you give, the fuel-sheet and debrief photos you attach, and your acknowledgements of company circulars are sent to your airline's own Flight Control server. Your airline holds them under its own policy, and Sky Matrix does not receive or keep them.
• Reading a fuel-sheet photo happens on your airline's server, using the AI service your airline has chosen, or not at all if your airline has it switched off; the app then shows no read button. For Sky Matrix's own airline, the photo is read by Sky Matrix AI through our service and sent with nothing else: no device, licence, flight or name.
• Company circulars and their PDFs come from your airline's server and are kept on your device so you can read them in flight.
• The offline flight-plan reader is delivered by your airline's server, marked for your device, in place of a personal subscription.

For what your airline does with this information, ask your airline: it is the one holding it.

Third-party services

Each provider processes data under its own privacy policy. We share only what the feature you invoked requires. Anonymous usage milestones — so we can see where people get stuck, the app records that a step happened (app opened, OFP loaded). Only your Device ID and the step name are sent — never OFP content, route, times or any flight data.

Security model

• Licences are protected with an ECDSA P-256 digital signature, only our server holds the private key, so codes can't be forged, and each code is bound to a single device (a subscription covers two devices, so you hold one code per device).
• Your PIN is stored as a salted one-way hash; biometric unlock uses the platform authenticator (WebAuthn) and never exposes your fingerprint/face to the app.
• Our Android apps are signed with our own private release key, Android verifies that signature on install and will only accept future updates signed with the same key.
• The app is served only over HTTPS. Sensitive data is never placed in URLs.
• Honest caveat: any client-side gate deters casual access but is not a guarantee against a determined attacker. Use a strong PIN and keep your device secured.

Android APKs, verify before you install

If you sideload one of our Android apps, confirm the file is authentic by checking its SHA-256 checksum against the matching value below before installing.

The file checksum changes with every release. The signing certificate does not — it identifies the developer, and it is the stronger of the two checks: a file that hashes correctly but is signed by someone else is not our build. To verify it, run apksigner verify --print-certs -v <file.apk> and match the value printed as Signer #1 certificate SHA-256 digest. Our APKs are signed with APK Signature Scheme v2, so keytool will wrongly report them as unsigned — use apksigner.

To check a file, on Windows run certutil -hashfile <filename> SHA256, or on macOS/Linux shasum -a 256 <filename>. The output must match the value above exactly. These checksums are for the current published builds; each one changes whenever that app is rebuilt.

Only install an APK obtained from our official download or checkout link. Because these apps are sideloaded, Android will warn about "unknown sources", that is expected; the checksums above are how you confirm the file hasn't been tampered with.

Your choices

You can stop all outbound data by simply not using the online features, the core briefing works offline. Waypoint sharing and sending a flight to your own second device each have their own switch in INIT → Settings → Privacy. To delete your data, clear the app's storage on your device. For a licence transfer or account/data request, email admin@skymatrix.biz.

Contact

Questions about privacy or security: support@skymatrix.biz.