DeltaV Academy vs FredSky

Delta-V Academy is a hands-on 3D simulator for learning how orbits actually work. Spin the Earth, drag a satellite into orbit, change its altitude or shape, and watch orbital mechanics respond in real time. No math background is required to start, with enough depth to challenge people who already know the difference between a Hohmann transfer and a ground track. WHAT YOU CAN DO - Fly ten guided lessons that build from the basics to full space situational awareness, each written for four levels: Kids, Novice, Intermediate, and Advanced. - Adjust altitude, eccentricity, and inclination with live sliders and see period, speed, and ground tracks update instantly. - Watch guided mission replays, including Apollo 11’s flight from Earth parking orbit into lunar orbit, an ISS rendezvous, and JWST’s cruise to L2. - Build satellite constellations and Walker deltas, then study their coverage. - Explore sensor geometry and space domain awareness with ground radar and space-based trackers. - Trigger a Kessler debris cascade and see why orbital congestion matters. - Capture screenshots and video of your own missions. LEARN AT YOUR LEVEL Pick Kids mode for plain-English labels and a friendly guided path, or step up to Advanced for J2 perturbations, oblate-Earth ground tracks, and multi-sensor architectures. Switch anytime. MISSION ARCHITECT Describe a mission in plain English and Delta-V Academy builds it for you in the simulator. Free accounts include three generations per day. FREE TO LEARN Kids and Novice tracks are free. Pro unlocks higher tracks, scenario JSON exports, the Walker builder, and 40 Mission Architect generations per day. Lifetime includes the same features with 15 generations per day. Lesson 1 of every track is available without an account. Whether you are a student, teacher, space enthusiast, or professional seeking an intuitive understanding of orbital mechanics, Delta-V Academy turns abstract equations into something you can see and steer. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.deltavacademy.com/privacy

FredSky turns your iPhone into a pocket planetarium. Look up, then at your phone, and instantly see what's overhead right now — the stars and constellations, the Moon and planets, and satellites passing over. The all-sky chart is centered on the zenith, like lying back and looking straight up, drawn for your exact location and moment. Raise your phone toward the sky and FredSky switches to a live camera view with the brightest objects labeled where you're aiming. Lower it, and you're back to the chart. • Live star chart — stars to naked-eye brightness, the classic constellation figures, the planets, the Moon at its true phase, and visible satellite passes. • Fully offline — the entire star catalog is built in, so the sky is right whether or not you have a signal. • Point-and-look — hold your phone up to identify the bright star or planet you're looking at. • Bird songs, too — tap record and FredSky identifies the bird singing nearby, then keeps your sightings as an illustrated life list. • Red night mode — a one-tap, dark-adapted view that protects your night vision outdoors. No account. No ads. No tracking. Just look up. Positions, phases, and pass times are computed properly — the numbers stay serious, even though the whole app is built to answer one question fast: what is that?