Polarisetter: True North

True north and a level indicator for setting up a telescope at night — on a dark-sky-friendly red screen.

Polarisetter is a small companion app for setting up a telescope at night. It shows you true north (not magnetic north) and the device's level — on a single dark-sky-friendly screen — so you can polar-align your mount quickly in the dark.

Aligning an equatorial mount needs true north, not magnetic north. At the same time, the tripod has to sit level. Polarisetter brings both readouts together so you can finish the setup with fewer back-and-forth glances.

KEY FEATURES

• True North Combines the device's gyroscope and magnetometer with your latitude and longitude to correct for magnetic declination. Stripped down to what telescope setup actually needs — no map widgets, no clutter.

• Level Indicator Real-time tilt readout. Place the device on the mount head while extending the tripod legs and you'll know the moment it sits flat.

• Dark-Sky Friendly UI Black background with red text. Bright screens contract your pupils and cost you the dark adaptation that lets you see faint stars. Polarisetter uses the same red-light convention astronomers have followed for decades.

• Works Offline No network required. Your location is used only on-device to compute magnetic declination — it never leaves your phone.

WHO IT'S FOR

• Telescope users observing or imaging nebulae, clusters, planets • Anyone who wants polar alignment to be less of a chore • People who don't want a bright screen blasting their night vision • Campers, hikers, and other outdoor folks who'd rather keep things dim

HOW TO USE

1. Open Polarisetter outdoors with a clear view of the sky.
2. Allow location access if prompted — your latitude and longitude are used only to compute true north (nothing is sent off-device).
3. Place the device on a level surface or mount head and align your telescope to the displayed bearing.

REQUIREMENTS

• iOS 15.6 or later • Location access (used to compute true north)

About the developer Built by an indie developer. Feedback and bug reports are welcome at karaage01@outlook.jp or @krgpi on X.