Shock Math Calculator vs Horizon
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Shock Math Calculator
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Shock Math is a fast, accurate compressible-aerodynamics calculator for students, engineers, and anyone working in high-speed gas dynamics. Solve isentropic, shock, and duct-flow relations in seconds — from any input variable, for any gas. COMPRESSIBLE FLOW, SOLVED • Isentropic flow — pressure, temperature, density, and area ratios, Mach angle, and Prandtl–Meyer angle • Normal shock relations — downstream Mach, static and stagnation pressure, temperature, and density ratios • Oblique shock relations — weak and strong solutions, wave angle, deflection angle, and normal Mach components • Conical shock relations — Taylor–Maccoll solution for cone angle, surface Mach number, and surface property ratios • Fanno flow — adiabatic flow with friction in a constant-area duct • Rayleigh flow — frictionless flow with heat addition • Standard atmosphere — U.S. Standard Atmosphere 1976 from sea level to 86 km: temperature, pressure, density, speed of sound and viscosity, from altitude, pressure or density • Ideal gas law — p = ρRT and pV = nRT, solve for any quantity in the units you work in • Scratch Pad — a quick built-in calculator for the numbers in between SEE THE PHYSICS Every result comes with a chart: property ratios across the Mach range with your answer marked, the full θ-β-M oblique shock diagram with your case on it, the cone-angle curve for conical shocks, and atmosphere profiles by altitude. SOLVE FROM ANY VARIABLE Don't just go forward from Mach number. Enter a pressure ratio, temperature ratio, area ratio, wave angle, or Prandtl–Meyer angle and Shock Math finds the Mach number for you — subsonic or supersonic branch, your choice. ANY GAS, ANY GAMMA Set the ratio of specific heats (γ) to model air, combustion products, monatomic gases, or anything in between. Every relation respects your γ. PROVEN-ACCURATE MATH Version 1.6 rebuilt and independently verified the calculation engine. Every relation is cross-checked against the classic NACA Report 1135 tables and against independent reference implementations across a wide range of Mach numbers and specific-heat ratios — hundreds of checks, zero discrepancies. Forward and inverse solutions round-trip exactly. BUILT FOR REAL WORK • Clean, consistent calculators that remember your inputs • Theory & Equations: assumptions and key equations for every calculator, one tap away • History and saved cases — reload any past calculation • Export results as text, CSV or PDF • iPad layout with a sidebar, plus Split View and Stage Manager • Apple Watch app: isentropic flow, normal shock, ideal gas and a scratch pad, set with the Digital Crown • Siri and Shortcuts actions for isentropic ratios, normal shocks and the standard atmosphere • Light and dark mode, VoiceOver, and every text size • Show or hide the calculators you use Whether you're checking homework in a gas dynamics course, sizing a supersonic nozzle, or sanity-checking a CFD result, Shock Math gives you trustworthy numbers fast. Feedback and feature requests are always welcome from the in-app form.
Horizon
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Hold up your phone and watch the night sky come alive. Horizon-AR uses your camera, GPS, and device motion to place real-time augmented reality overlays exactly where celestial objects appear in the sky above you. TRACK THE SOLAR SYSTEM Follow the Moon, Sun, Mercury, Venus, Mars, Jupiter, and Saturn with a live arc overlay showing each object's full path across the sky tonight. Rise and set times update in real time based on your precise location. 110 MESSIER DEEP-SKY OBJECTS IN AR Activate Hot Targets mode and see every Messier object currently above your horizon floating in the AR view — galaxies, nebulae, open clusters, and globular clusters, each colour-coded by type. Tap any label to open a detail card showing: • Object type and Messier catalogue number • Common name (Andromeda Galaxy, Orion Nebula, Pleiades…) • Current altitude above the horizon • Apparent visual magnitude • Recommended instrument — naked eye, binoculars, or telescope • Favourite toggle, saved across sessions When objects cluster together, a single tap fans them out radially so you can reach each one individually. FILTER BY OBJECT TYPE Narrow the Hot Targets overlay to just galaxies, just nebulae, or just star clusters with a single tap. Objects you've starred appear in your Nightly Overview for quick access every session. FREEZE THE SKY Long-press anywhere to lock the entire AR view — overlays and camera image — as a still frame. Perfect for star parties, sketching, or sharing a screenshot. Tap once to unfreeze. NIGHTLY OVERVIEW Open the Tonight sheet for a full list of rise, transit, and set times for all solar system objects plus your Messier favourites, sorted for the coming night at your location. WORKS WITHOUT FULL PERMISSIONS No camera access? Horizon-AR switches to a star-field background with altitude rings and an azimuth grid so you can still explore the sky. Declined location? Enter coordinates manually and continue without interruption. No account. No subscription. No ads. Privacy: your location and camera data never leave your device.
Screenshots
Verdict
The clearest difference is update cadence: Shock Math Calculator at every 3 weeks against Horizon's every 2 months. Horizon's advantage is iOS requirement (15.1 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Shock Math Calculator ships an update every 3 weeks, Horizon every 2 months. The most recent releases landed on October 5, 2026 and October 23, 2026 respectively.
| Parameter | Shock Math Calculator | Horizon |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 3 weeks — better | Every 2 months |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPad, Apple Watch — better | iPhone, iPod |
| Requires iOS | 17.0 | 15.1 — better |
| Further details — not scored | ||
| Size | 5 MB | 42 MB |
| Age rating | 4+ | 4+ |
| Developer | Gregory Manley | Michael Bartos |
In-app purchases
Shock Math Calculator
No in-app purchases
Horizon
No in-app purchases
Questions
Is Shock Math Calculator free?
Is Horizon free?
Do Shock Math Calculator or Horizon have ads?
Which is updated more often, Shock Math Calculator or Horizon?
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