Celestia vs WeekdayWiz

Celestia — real-time 3D visualization of space 3D Space Simulator | Celestia lets you explore our universe in three dimensions. Celestia simulates many different types of celestial objects. From planets and moons to star clusters and galaxies, you can visit every object in the expandable database and view it from any point in space and time. The position and movement of solar system objects is calculated accurately in real time at any rate desired. Interactive Planetarium | Celestia serves as a planetarium – for an observer on any celestial object. You can easily navigate to any world and land on its surface. When used as a planetarium, Celestia shows accurate positions of solar system objects in the sky. You can switch labels and other supporting features on and off with hotkeys, or zoom in and out on an object of interest, for example Jupiter’s system of moons. Expandable Content | Customize Celestia according to your needs. Celestia’s catalogues can be easily expanded. There are many different add-ons available containing new objects like comets or stars, high-resolution textures of Earth and other well mapped solar system bodies, as well as 3D models for asteroids and spacecraft on precise trajectories. Even fictional objects from well-known sci-fi franchises can be found. EULA(End User License Agreement): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

WeekdayWiz turns a party trick into a real skill. Want to know what day of the week your birthday falls on in 2034? Or whether 14 July 1789 was a Tuesday? Most people reach for a calendar app. With WeekdayWiz, you train your brain to do it in your head — in under 3 seconds. The method is a 9-step mental calculation tuned for dates between 1900 and 2099. Sounds intimidating? It isn't. You can master it in about a week of focused practice. — BUILT FOR LEARNING — • A guided Wizard walks you through every step on a real date, with explainers tuned to absolute beginners. • Practice mode reveals each step on tap, so you can hint your way through until the algorithm sticks. • Speedrun modes drill one skill at a time — month codes, mod 7 arithmetic, leap-year corrections — under a timer that pushes you faster. — TRACK YOUR MASTERY — • 12 distinct training modes from "Day of month mod 7" all the way to the Full Algorithm. • Master a mode by hitting 25 correct in a row, under the goal time (typically 3–6 seconds per answer). Progress shows as mastery badges on the home screen. • Personal bests, run history, achievement grid for all 12 modes. — REAL-TIME PACING FEEDBACK — A per-question alarm fires the moment you cross your time budget — so you feel yourself slipping before the answer is even given. — DESIGNED FOR DAILY PRACTICE — • Pull-to-refresh: a fresh random date. • Date picker for testing specific days (your birthday, a historical event, a future plan). • Light and dark themes, system-aware. • iCloud sync keeps your records consistent across iPhones (Pro). — FREE & PRO — The wizard, all step explainers, every method walkthrough, and practice mode stay free forever. Pro unlocks the timed training modes, the mastery system, and iCloud sync — one-time purchase, yours forever. 7-day free trial included. Master the calendar. Without the calendar.