Moon Theory

Moon phases & night-sky guide

Only for iPhone

$1.99 · Designed for iPhone. Not verified for macOS.

iPhone

Moon Theory is now a full night-sky observatory: live star map with red night mode, tonight's observing plan, seeing forecast, and ISS, meteor & aurora alerts. Moon Theory is a quiet, private observatory for your pocket. Everything is computed right on your device — no account, no sign-in, no analytics, and no data collected, ever. TODAY A large, live moon glyph drawn from the real illuminated fraction, with phase name, illumination, moonrise and moonset, and countdowns to the next new and full moon. A "through the telescope" card shows tonight's terminator and libration — where along the lunar limb to point your optics. TONIGHT Your observing plan, assembled automatically. The dark-sky window between dusk and moon interference, tonight's best deep-sky targets for your sky, visible planets, a seeing forecast built from jet-stream winds, active meteor showers, ISS passes, and an evening timeline. SKY A live star map of your sky right now. Pinch to zoom from wide field down to 20°, pan around the horizon, and tap any star, planet, or deep-sky object for its field card. Constellation and ecliptic overlays help you find your way. Red night mode preserves your dark adaptation at the eyepiece. CALENDAR A month grid with a phase glyph on every day; new, quarter, and full days marked. Tap any day for its phase and rise/set times. ALERTS Local notifications, on your terms: phase events with custom lead times, moonrise and moonset alarms, ISS passes over your location, meteor-shower peaks, and aurora watches when geomagnetic activity spikes. IT TEACHES AS YOU GO Every number explains itself in plain language, and unfamiliar terms unfold into two-sentence field notes when tapped. Each night the app surfaces one earned insight about your sky. Swipe between tabs or tap the bar — the whole app is built for one-handed use in the dark. PRIVATE BY DESIGN No account, no analytics, no tracking, no ads — and nothing about you is ever collected or stored remotely. The core app is fully offline: moon, planets, stars, and calendar all compute on-device. Online extras — cloud and seeing forecasts, space weather, satellite orbits — are fetched anonymously with no identifiers: the forecast request carries your coordinates and nothing else, the response is used once, and nothing about you is retained. Off the grid, the app quietly falls back to everything it can compute offline. Whether you're planning tonight's session at the eyepiece or just love knowing what the sky is doing, Moon Theory keeps the night at your fingertips — quietly, accurately, privately.

Ratings & Reviews

  • 5.0
    out of 5
    1 Ratings

Moon Theory's first update brings the night sky into sharper focus: • Red night mode — a deep-red shade that protects your dark adaptation at the eyepiece • New alerts: ISS passes, meteor-shower peaks, aurora watches, and moonrise/set alarms • Tonight's targets — an automatic observing plan for the best deep-sky objects tonight • Seeing forecast and a "through the telescope" card with terminator and libration detail • Pinch to zoom the sky view (20–90°), tap any object for its field card • Every number now explains itself — inline glosses and tap-to-reveal field notes • A new thin-crescent identity to match the app's quiet observatory feel

Version 1.1.0

The developer, Jared Landt, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    Jared Landt
    Size
    46 MB
    Category
    Weather
    Compatibility
    Requires iOS 15.1 or later.
    • iPhone
      Requires iOS 15.1 or later.
    • iPod touch
      Requires iOS 15.1 or later.
    • Mac
      Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    English
    Age Rating
    4+
    Copyright
    © 2026 Jared Landt
  • Privacy Policy

    • Supports

    • Family Sharing

      Up to six family members can use this app with Family Sharing enabled.