RPN Memory Calculator vs DeepSpace

RPN Memory Calculator is a simple to use reverse polish notation calculator with seven functions and memory operations including a memory value display and three visible registers. This is not intended to be a full scientific function calculator, it is a handy implementation of basic calculator operations using RPN. The calculator also integrates unit conversions, so you can convert the value in the x register. This allows you to choose a type (Speed, Mass, Temperature, Pressure etc) and then pick a from and to type. The converted number can either be accepted back into the x register, or discarded. The calculator remembers state so that calculations you have been working on, with results stored in either the memory field or any of the registers, will still be present when re-open the app any time in the future. All registers, even the hidden ones above z are stored.

DeepSpace — Star & Planet Viewer Point your phone at the sky and see the stars move in real time. DeepSpace turns your device into a personal star atlas — no account, no subscription, no internet required. What's in the sky tonight? Hold up your phone and explore 95 named stars rendered in color by spectral type, all 8 planets, the Sun, and the Moon — their positions calculated from simplified orbital models and updated live. Accurate enough for casual stargazing and learning the sky; not a precision instrument. Features • Gyroscope sky map — point anywhere and the stars follow, at up to 120fps on supported devices • 16 constellations — tap any to see its mythology and star pattern • 110 Messier objects — galaxies, nebulae, and clusters plotted and tappable • Tap to lock on — tap any star or planet for its magnitude, coordinates, spectral type, and more • Sky search — find any object by name and jump to it instantly • Tonight's Sky — one tap shows what's visible right now: planets above the horizon, best deep-sky objects, and current moon phase • Time Machine — scrub forward or backward in time to plan or revisit a night • Observation journal — log your sightings with date, location, and notes • Celestial event alerts — get notified about oppositions, conjunctions, and lunar events for objects on your watch list • Milky Way overlay — the galactic band drawn across the sky • Red Night Mode — full red filter to protect your dark-adapted vision at the eyepiece • Share the sky — share a snapshot card of tonight's sky with friends • Portrait and landscape — works in any orientation on iPhone and iPad Honest about accuracy Star and planet positions use simplified orbital models this is great for finding constellations, identifying planets, and learning the night sky. For precise observation planning, pair it with a professional ephemeris.