SkyEngine vs Black Hole Sandbox

SkyEngine is a realistic night sky viewer that transforms your phone into a portable planetarium. Whether you're camping under the stars or winding down for sleep, SkyEngine brings the beauty of the night sky to your fingertips. Point your phone at the sky and see exactly what's above you. SkyEngine uses your GPS location and compass to show an accurate, real-time view of stars, planets, and constellations from wherever you are. FEATURES Realistic Sky Rendering — Thousands of real stars rendered with accurate positions and brightness — Planets including the Moon, visible in their true locations — The Milky Way stretching across your sky — Realistic sky colors from sunset through deep night Compass Mode — Point your phone at the sky and the view follows — Labels appear on stars and planets as you look around — Constellation lines guide you through the night sky Ambient Sounds & Sleep Mode — Campfire crackling, crickets, wind, water, and calming drone music — Mix and match sounds to create your perfect atmosphere — Sleep timer with gentle fade-out (15, 30, 60, or 90 minutes) Visual Effects — Shooting stars streak across the sky at random — Aurora Borealis shimmering on the horizon — Warm campfire glow from below Customization — Adjust light pollution (Bortle 1–9) to match your real sky — Search any city worldwide to see its sky — Time controls: jump forward, backward, or animate the sky at any speed — Toggle constellations, labels, deep sky objects, and grid overlay Perfect for camping trips, bedtime relaxation, astronomy learning, or simply enjoying the beauty of the night sky from anywhere.

A realistic black hole, in the palm of your hand. Black Hole Sandbox gives you a scientifically accurate black hole, ray-traced live on your iPhone. It traces light through curved spacetime using the equations of general relativity: light that comes too close falls into the shadow, and light that passes nearby bends around it. The galaxy behind stretches into arcs, the far side of the disc lifts above and below the shadow, and a thin ring of photons wraps its edge. Orbit it, zoom in, and watch the light bend as you move around it in real time. TWO WAYS TO SEE IT • In-app 3D: set it against a whole galaxy or a field of stars, and watch the lensing bend everything behind it as you orbit around it. • In augmented reality: the star of the show! Put it in your living room, sit it on a table, and walk around it as it warps your room behind it. DESIGN YOUR OWN Go beyond realism and let's see your creativity! Free, to get you started: • Shape and disc: start grounded. Set the size of the shadow, how bright the photon ring burns and how far its glow reaches, and the gap, width and tilt of the accretion disc. • Presets: twelve come built in, and you can save as many of your own as you like. Unlock the full designer with a single one-time purchase. No subscription. • Color and light: dial it up a notch. Choose from 37 palettes of single and dual color combos, or pick your own inner and outer colors, and set how brightly the disc glows. • Texture: wrap the disc in 14 dynamic textures, from smooth swirls and drifting wisps to bands, clumps and cells. Set their strength and detail, spin the disc faster or slower, and add wind to curl the swirls tighter toward the center. • Facets: break the disc into 14 geometric patterns, like triangles, diamonds, scales, spirals and gems, then set the size of the cells and how fast they turn to create a shimmer. • Emojis: feed it your favorite emojis and watch a swarm of them orbit the shadow, glowing as they go. Change their size, density, and how they tumble. • Photos: make one of your own photos the accretion disc and watch it spin around the abyss. Bought Black Hole Sandbox before it was free? The full designer is already yours. Build either a realistic black hole or one that could never exist, then set it on your coffee table.