Watcher of the Skies

01 — Where the numbers come from

Positions, altitudes and speeds never leave the box. Only a registration lookup does, and only if you leave it switched on.

It talks to your box.
Not to a company.

Point it at the Raspberry Pi running dump1090 on your own network. It probes the known data paths — dump1090, skyaware, tar1090 — finds the one that answers, and remembers it. You never have to know which front-end you installed.

Positions, altitudes, headings and speeds are decoded by your receiver and never leave your network. Registrations and routes come from adsbdb.com, free and account-free, and you can switch that off entirely.

02 — The one thing colour means

Height
is a hue

In the app there is no key. There doesn't need to be — warm on the deck, cool at cruise, and you have it in about a minute.

Squawking 7500, 7600 or 7700 — red at any height
Address in a military block — purple at any height

Above 30,000 ft

15,000 – 30,000 ft

5,000 – 15,000 ft

Below 5,000 ft

On the ground

03 — Everything it does

Ten things,
done properly

Map, list, inspectorA real NavigationSplitView. Click an aircraft on the map, the row selects. Click the row, the map follows.
Range rings10, 25 and 50 nautical miles, drawn from your antenna's published position. ⌘0 recentres.
TrailsWhere each aircraft has been since you started watching, faded by age.
Emergencies go red7500, 7600, 7700 override the altitude ramp entirely. A hijack code is not a shade of teal.
NotificationsOverhead, military, or emergency — your choice. Keyed and cooled down for 30 minutes so one aircraft can't fire sixty times.
Shortcuts & Siri“What's Overhead” and “Count Aircraft in Range,” as App Intents.
Keep in frontFloats above other apps, including full screen. A window you glance at, not one you visit.
1s / 3s / 10sDrawing the map is where the energy goes, so refresh rate is the battery lever. Tracking never stops.
Feet or metresKnots and nautical miles by default, because that is what aviation speaks. Metric if you insist.
No dependenciesSwift 6, strict concurrency, zero data races, sandboxed, no third-party code at all.

Idle CPU: about zero. No polling timers. No display links spinning over a sky where nothing is moving.

The window, roughly actual size — small enough to park in a corner of the screen and forget, until something interesting comes over the ridge.

Performance budget · cold launch under 400 ms

The Watcher of the Skies window: aircraft over the antenna, coloured by altitude

One person. One antenna.
Whatever happens to pass over.

That is the entire product

04 — When you can have it

Not yet

It runs. It has run every day since it was built, on one Mac, pointed at one antenna in Tennessee.

What it doesn't have yet is a signature, a notarisation ticket, and the hundred small courtesies an app owes a stranger's machine. When it has those, this page changes and you get a download.

Tell me when it ships

No list, no tracking, no drip campaign — an email to a person, who will send you exactly one back.

What it will want

System: macOS 15 or later, Apple silicon or Intel
Receiver: Any dump1090-family box you can reach — dump1090-fa, tar1090, or mutability
Position: Set LAT and LON in dump1090's config and the range rings appear on their own

It talks to your box.Not to a company.

Heightis a hue

Ten things,done properly

Not yet

It talks to your box.
Not to a company.

Height
is a hue

Ten things,
done properly