Selene is a quiet, beautiful moon-phase almanac that works entirely offline. No
ads, no accounts, no internet — just the Moon, drawn on your screen exactly as it
appears in the sky tonight.
Every phase in Selene is computed on your device from the mean synodic month (the
29.5-day cycle from one new moon to the next). Open the app anywhere, at any time,
with no signal at all, and Selene will tell you where the Moon is in its cycle.
TONIGHT
Open to a hand-drawn Moon showing tonight's true illuminated fraction and
terminator — the curved line dividing light from shadow. Read the phase name, the
percentage lit, and the Moon's age in days. See the exact dates of the next full
moon and the next new moon at a glance, and save any night you'd like to remember.
CALENDAR
Browse any month as a grid of tiny moon glyphs, each one drawn to the correct
phase for that day. Step backward and forward through the months and tap any date
to reveal its phase, illumination and age. Plan a stargazing trip around the new
moon, or find the next full moon for a night walk.
GUIDE
Learn the eight principal phases — New, Waxing Crescent, First Quarter, Waxing
Gibbous, Full, Waning Gibbous, Last Quarter and Waning Crescent — each with its own
drawn moon and a short, practical description of when and where to look for it.
NAME THE PHASE
Test yourself in a gentle quiz mini-game. Selene draws a mystery Moon and you pick
the phase it shows. Correct and incorrect answers are confirmed with distinct
vibration patterns — never sound — and your best score is kept on the device.
ALMANAC
Collect your saved nights in one place, each with its moon glyph and phase, and
unlock quiet awards as you save dates and sharpen your quiz score.
DESIGNED FOR CALM, PRIVATE USE
- Fully offline. Selene never connects to the internet and requests no location.
- No advertising, no analytics, no third-party trackers.
- No account and no sign-in. Your saved nights and best score stay on your device.
- The only permission Selene uses is vibration, for quiz feedback.
- A deep-indigo night theme with an elegant serif face and a silver, softly
cratered Moon rendered on a custom canvas.
A NOTE ON ACCURACY
Selene uses a mean synodic-month approximation referenced to a known new moon. This
is wonderfully reliable for learning the phases, following the cycle and planning
around full and new moons. It is an educational almanac, not a precision ephemeris,
so exact rise and set times for a specific location are outside its scope.
Whether you're a night-sky beginner learning to read the Moon, a photographer
chasing the full moon, or simply someone who likes to know what's overhead, Selene
keeps the almanac in your pocket — calm, private and always available.
Offline moon phase almanac — tonight's phase, calendar, guide and quiz.