Lantern Field

Lantern Field is a small private world clock that turns every city you track into a hanging amber lantern. Your home city glows brightest in the centre; every contact you add becomes another lantern in the field, dimmer if it is night for them, bright and warm if it is day. Read the field at a glance and you know who is awake, who is in working hours, and who is asleep -- without doing hour math. The action lives at the BOTTOM RIGHT -- you tap the big amber lantern button to hang a new lantern.

THE FIELD

A wide horizontal "hanging lantern row" sits at the very top. Each lantern hangs at a height that maps to its city's hour-of-day -- noon hangs HIGHEST, midnight sits lowest. The colour of the lantern's glow tells you the light: bright amber for working hours, soft amber for off-hours daylight, deep ember for night. Read the row left-to-right by hour offset from home.

THE TILE GRID

Below the row, your contacts live as a 2-COLUMN GRID of square TILES instead of a long list. Each tile has:
- a big glowing lantern at the top with the local time inside the glow
- the contact's name in bold sans
- the city + IANA timezone in a small caps mono
- a delta pill ("+5h", "-3h") on the right
- a warm/cool background that shifts with day vs. night

Pinned contacts get an extra ember ring around the lantern.

THE BOTTOM BAR

A permanent "YOU ARE IN" bar lives at the bottom edge: your home city, your local time, and the longest overlap window when everyone in the field is in working hours -- "WINDOW 14:00 - 17:00". The bar always tells you where you are and what window everyone shares.

THE LANTERN BUTTON

A big round amber LANTERN button floats at the bottom-right corner. Tap it and a compose sheet rises up: name, city picker, notes. The button is the most reachable spot on the screen by design, so adding a new lantern is one thumb-tap away.

THE ATLAS TAB

The second tab is an "Atlas" -- every unique city you track, sorted by hour offset, rendered as warm parchment rows. Each row: city label, IANA id, day-shift hint, contacts in that city, delta badge, big local time. A + ADD CITY pill top-right opens the same searchable picker. Long-press a row to remove all contacts in that city.

THE EDITOR

Tap a lantern tile to open the editor. Name field, city picker (115+ IANA cities plus raw UTC offsets), free notes field. Save, pin, archive, or delete from a row of action buttons at the top.

SETUP

Pick your HOME city. Add a custom display label. Toggle 24h vs 12h clock. Tune the working window to any whole hour 0-23 using +/- steppers or by typing.

PRIVACY

Lantern Field keeps every lantern on your device. No sign-in, no cloud sync, no analytics, no ad SDK. The store is encrypted at rest with a key that lives in the Android Keystore. No network permissions are requested. If you uninstall the app, the data goes with it.

WHO IT IS FOR

- distributed engineering and product teams scheduling syncs across continents
- founders running calls with offices in different regions
- account managers and recruiters coordinating across timezones
- freelancers juggling clients across the EU, the Americas, and Asia
- anyone with family or close friends in another timezone who is tired of doing the hour math in their head

NO ACCOUNTS. NO CLOUD. NO ADS. JUST LANTERNS.