Comparison

Curvature vs Simple Solar

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Curvature

This app provides advanced tools for calculating and visualizing earth measurements, including curvature, horizon distance, and drop distance. It features a redesigned interface with precision mapping, data persistence, and a knowledge hub with research resources.

Highlights
  • Advanced Earth Calculators
  • Graphic Result Visualization
  • Precision Mapping Tools
  • Data Persistence with SwiftData
  • Expanded PDF Library
  • Universal Unit Converter
  • Save & Export Calculations
Features
Read full description

Curvature is a geometry and visibility toolkit for anyone who wants to test what a curved or flat Earth would predict, with every formula documented and every assumption stated. THE CALCULATOR Enter observer height, target height and surface distance. Curvature returns the surface horizon, tangent-plane drop, midpoint bulge, horizon dip, surface tilt and the hidden and visible portions of the target, in metres or feet, kilometres or miles. Choose refraction off, four published coefficients or your own k from 0 to 0.5, and compare any result side by side with the pure geometric case. Drag the observer, target and distance directly on an exaggerated profile, or switch to a true-scale view with a magnified detail inset. Uncertainty ranges recalculate across your stated input tolerances so you can see whether a sighting is robust. THE MAP Drop rulers and points of interest on standard, satellite or hybrid maps. Rulers report geodesic surface distance and initial bearing in degrees or NATO mils, search for places, fit the view and send endpoints straight to the calculator. Optional terrain lookup prefills ground elevations from SRTM data with the datum and limits spelled out. THE 3D MODEL EXPLORER (NEW) Explore three scenarios with the same observer, date and time: the classical north-polar disc, a south-polar projection comparison and a WGS84 reference ellipsoid. The globe uses dated geometric ephemerides from the open-source Astronomy Engine, including sidereal rotation, precession, nutation, seasons, real Earth-Sun and Earth-Moon distances and lunar illumination, validated against JPL Horizons and US Naval Observatory data. Place the observer anywhere, read elevation, bearing, slant distance and angular diameter for the Sun and Moon, then open the observer sky to see both at their calculated angular size. A comparison sheet lists all three models for the same inputs. Each scene labels what is sourced, what is an app assumption and what is not simulated. REPORTS AND ANALYSIS Export an illustrated PDF report with inputs, coordinates, assumptions, uncertainty bounds and the calculation version, or copy a structured text summary. On supported devices, Apple Intelligence can draft a plain-language analysis that never alters the calculated numbers. REFERENCE LIBRARY Read bundled historical and technical PDFs with page bookmarks, find and go-to. Browse fifty curated web links covering tools, research, forums and video from every perspective, plus references, worked formulas for the calculator, map and explorer, and an indexed glossary of more than eighty terms. YOUR DATA Saved observations, rulers, points, links, imported PDFs and reading positions sync privately through iCloud on signed-in devices, with portable backup and restore. No account, tracking or advertising. Curvature does not tell you what to believe. It shows what each model predicts, how that was calculated and where the model stops.

About

Simple Solar

Features
Read full description

Simple Solar is the fastest, simplest way to control your SunSynk inverter. Make changes in seconds, not minutes — no clutter, no confusing menus, just clear control. Edit battery schedules instantly with a powerful visual editor, or use quick toggles to override charging, discharging, and grid export on the fly. Monitor your solar generation, battery status, and home energy consumption in real time from one clean, reliable dashboard. Core Features: • Edit battery schedules in seconds with an intuitive visual editor • Instant on/off toggles for battery charge, discharge, and export • Real-time energy flow visualisation • Daily, weekly, and monthly energy statistics • Support for multiple plants and parallel inverters Simple Solar Pro unlocks advanced automation: • Smart Tariff Integration – Automatically charge during cheap Octopus Intelligent Go slots • Custom Schedules – Fine-grained time-based rules for grid and battery control • Push Notifications – Alerts for low battery, high load, and system events • Monthly Reports – Detailed energy summaries exportable as PDF • Ad-free experience • Smart Tariff Automation – Supports Octopus Intelligent Go, Cosy, Flux and Go, plus E.ON Next, EDF GoElectric, British Gas, ScottishPower, Good Energy and fully custom tariffs. Automatically charge your battery during the cheapest slots, including extra cheap “bump” slots your provider signals through the day, and sell stored energy back during peak export periods or before your guaranteed cheap period starts. • Solar-Aware Charging – Only tops up from the grid by as much as your predicted solar won’t cover, helping you avoid over-buying energy. • Custom Schedules – Fine-grained time-of-use rules for grid and battery control. • Push Notifications – Alerts for low battery, high load and system events. • Monthly Reports – Detailed energy summaries exportable as PDF. • Ad-free experience. Terms of Use: https://minutiamobile.com/marketing/simpleSolar/terms.html Privacy Policy: https://minutiamobile.com/marketing/simpleSolar/privacy.html

Screenshots

Curvature4 screens
Simple Solar4 screens

Verdict

The call

The clearest difference is price: Simple Solar at Free against Curvature's $1.99. Simple Solar also leads on update cadence (every 3 weeks vs every 5 months). Curvature's advantage is in-app purchases (none vs 4). On ads, device support and iOS requirement 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

CostPrice · In-app purchases · Ads · Monetization

Simple Solar is free to download; Curvature costs $1.99 up front. Simple Solar sells 4 in-app purchases, starting at $6.99 per month. Curvature asks for nothing beyond the download.

UpkeepUpdate frequency

Curvature ships an update every 5 months, Simple Solar every 3 weeks. The most recent releases landed on October 24, 2026 and October 20, 2026 respectively.

Scorecard3 real differences · 7 level
Curvature versus Simple Solar: the parameters behind the verdict, then further details
ParameterCurvatureSimple Solar
Price$1.99Free — better
Rating5.0 (2 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings2 — better—
Update frequencyEvery 5 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaid—
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.616.6 — better
Further details — not scored
Size116 MB73 MB
Age rating4+4+
DeveloperSteven WilkinsonMinutia Mobile

In-app purchases

None

Curvature

No in-app purchases

4 purchases

Simple Solar

Subscriptions2
  • Automation7 Days trial$6.991 Month
  • Yearly Subscription7 Days trial$59.001 Year
One-time2
  • Remove Ads$2.99
  • Remove Ad's$2.99

Questions

Is Curvature free?
Curvature costs $1.99, with no in-app purchases.
Is Simple Solar free?
Simple Solar is free to download, with in-app purchases available.
Do Curvature or Simple Solar have ads?
Neither Curvature nor Simple Solar shows ads.
Which is updated more often, Curvature or Simple Solar?
Curvature ships an update every 5 months, and Simple Solar every 3 weeks. Most recently, Curvature was updated on October 24, 2026 and Simple Solar on October 20, 2026.

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