Every astronomy tool you need, in one app.

An astronomy weather forecast for the nights ahead: cloud, seeing, transparency, dew risk, wind and rain hour by hour, with each night rated and the best time to head out highlighted.

Weather data by Open-Meteo.com.

Sunset, each stage of twilight, when true darkness starts and ends, and when the Moon rises and sets, plus the best Moon-free nights in the coming month.

When each planet rises, is highest and sets tonight, and how well placed it is, with a simple rating and a day-by-day rise and set calendar.

Which of the 110 Messier galaxies, nebulae and star clusters are well placed tonight, when each is highest and how easy it is to see. Filter to what suits your telescope and keep your own Messier log.

A realistic Moon, lit and tilted exactly as you’ll see it from where you are, with earthshine on thin crescents. Rise and set graph, upcoming phases, supermoons, distance and libration. Works offline.

Every major shower’s peak and expected rates, whether the Moon will spoil it, and the best time to watch from where you are.

Your personal calendar of what’s coming up: eclipses with exactly how much you’ll see from home, planets at their best, close planet pairings, supermoons, meteor peaks, equinoxes and solstices.

When the Milky Way core is up during real darkness with no Moon, how high it gets and where to look, with a realistic sky view, nightly star ratings and your core season at a glance.

Sunrise, sunset, solar noon, golden and blue hour, the Sun’s path and day length through the year, plus today’s photo of the Sun from NASA’s Solar Dynamics Observatory, zoomable to study sunspots. Always use a proper solar filter.

Watch the planets move around the Sun on any date from 1900 to 2100, speed time up or slow it down, and tap a planet to see how far away it is and when it’s next at its best.

Where Io, Europa, Ganymede and Callisto are at any date and time, with a play button to animate them and the option to zoom right in, plus upcoming moon events, including when a moon or its shadow crosses the face of Jupiter.

A realistic, high-resolution view of Jupiter showing the Great Red Spot where it really is at any date and time. Press play to watch Jupiter rotate, and see the upcoming times the spot faces Earth that you can catch from your location.

Jupiter map: Hubble OPAL programme, NASA/ESA.

Each planet’s size, brightness, phase and height in the sky, with realistic views of each planet for the date, which side of Jupiter and Mars faces you, and the tilt of Saturn’s rings. It also shows how long you can record before the planet’s spin blurs detail, and whether your camera and Barlow give the right sampling.

Magnification, true field of view and exit pupil for your telescope, eyepieces and Barlow, your telescope’s limits, and a table covering your whole eyepiece collection.

Three calculators in one. Planetary: f-ratio, sampling, a suggested Barlow and region of interest. Deep sky: image scale against your seeing, and framing compared with Messier objects, plus field rotation and the longest sub-exposure on alt-az mounts. Camera and lens: the longest untracked Milky Way exposure, using the 500 rule and the NPF rule. Plus a field-of-view viewer: see your camera frame to scale on real photos of the Moon, planets and all 110 Messier objects, and compare up to three setups side by side.

Exactly where Polaris should sit in your polar scope right now, shown as a clock face (Sigma Octantis in the southern hemisphere), with a beginner-friendly explanation.