Quick Graph vs III
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Quick Graph
This powerful graphing calculator leverages multitouch displays for 2D and 3D equation visualization. It supports various coordinate systems and offers features like equation editing, evaluation, and a library for storing common formulas. Advanced features are available through an in-app purchase.
- 2D and 3D graphing
- Multiple coordinate systems
- Equation evaluation
- Equation library
- Copy/email/save graphs
- Implicit and inequality graphing (advanced)
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Quick Graph is a powerful, high-quality graphing calculator for iPhone and iPad, in 2D and 3D. "The app you need to survive the next semester." -- Gizmodo Type an equation and see it right away, written in math notation and drawn in a graph you can move, zoom and rotate with your fingers. Explicit and implicit equations and inequalities, in cartesian, polar, cylindrical and spherical coordinates, all fast and beautiful. What's inside: - 2D and 3D graphs with a clean, full-screen design. - 3D surfaces drawn with Metal: smooth shading, transparency, wireframe, and zoom that fills the screen. - Adaptive 2D drawing with exact roots and extrema and clean asymptotes. - Equation groups: show, hide and move several equations together, with a shared n. - Annotations with Apple Pencil or your finger on 2D graphs. - A math keyboard with functions, derivatives and more on each key. - Hyperbolic and inverse functions, min, max, if, derivatives. - Axes in decimals or multiples of π, and independent zoom on each 2D axis. - A library of example and saved equations, including groups. - Share as a link, image or text; copy and paste equations; drag them between windows. - Light or dark appearance, multiple windows on iPad, and support for iPhone Duo. Up to 6 equations can be shown at once in the free version. The Advanced Features, a single one-time purchase with no subscription, add: - More than 6 equations. - 2D and 3D implicit equations and inequalities. - The variable n with a slider, to animate your graphs. - 2D tracing with roots, extrema and intersections. - Value table. - External display support. - Decimal / π axes and polar range settings. No ads, no subscription. Please visit the website for more details.
III
Calculate material properties for III-V compound semiconductors like AlGaInAsP. It determines compositions, lattice constant, strain, bandgap, and effective masses for InP or GaAs substrates.
- III-V compound semiconductor calculations
- Material property determination
- Composition calculation (x, y, z)
- Lattice constant and strain analysis
- Bandgap and effective mass calculation
- Supports InP and GaAs substrates
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Application to calculate the compositions and material properties of a III-V compound semiconductor. Either InP or GaAs is assumed for the substrate. Some of the compositions and material parameters of the AlGaInAsP compound semiconductor are specified to determine the remain unknown parameters. The following properties are shown as a result: compositions (x, y, z), lattice constant, strain, bandgap, relative energy positions of the conduction and valence bands, and effective masses of the electron and holes.
Screenshots
Verdict
The clearest difference is price: Quick Graph at Free against III's $2.99. Quick Graph also leads on rating (4.6 vs 4.0) and ratings volume (423 vs 1). III's advantage is in-app purchases (none vs 2) and iOS requirement (11.0 vs 17.0). On review sentiment, ads 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
Quick Graph is free to download; III costs $2.99 up front. Quick Graph sells 2 one-off in-app purchases. III asks for nothing beyond the download.
Quick Graph holds the better App Store score, 4.6 against 4.0. That said, the two scores are not equally well evidenced: Quick Graph has 423 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 94% of Quick Graph's written reviews are positive against 100% of III's, so the app with the better star average is not the one people write more warmly about.
Quick Graph ships an update every 5 months, III every 17 months. The most recent releases landed on October 31, 2026 and November 6, 2026 respectively.
| Parameter | Quick Graph | III |
|---|---|---|
| Price | Free — better | $2.99 |
| Rating | 4.6 (423 ratings) — better | 4.0 (1 ratings) |
| Positive reviews | 93.6% of reviews | 100.0% of reviews — better |
| Number of ratings | 423 — better | 1 |
| Update frequency | Every 5 months — better | Every 17 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases — better | Paid |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 11.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | KZ Labs | Takuya Ishikawa |
Customer experience
Quick Graph
III
Bugs and requests
Quick Graph
Reported bugs
5 issues- Crashes when trying to save to photos
- Equations not visible when projecting to external display
- Incorrect rendering of some functions like y=tan(x)*x
- Degradation in 3D plot quality when zooming out
- Equations not working as expected for simple cases like x+y=0
Requested features
25 requests- Display 3D surface with variable opacity or as wireframe
- Ability to define and display functions over a certain interval
- Ability to define and display parametric equations
- Ability to move cursor around within a function while typing
- Ability to animate equations with a parameter
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- Ability to graph complex functions
- Ability to graph vector fields and slope fields
- Ability to graph parametric surfaces
- Ability to add vectors of given magnitude and direction
- Ability to add points in space using different coordinate systems
- Ability to add text labels in 3D space
- Ability to select and remove parts of 3D surfaces
- Ability to sum n terms of series
- Ability to graph inequalities
- Ability to graph Euler's formula
- Ability to identify coordinates of intersections and zeroes
- Ability to move and rotate the 3D axes
- Ability to change line weight and style for each function
- Ability to define and display functions in polar coordinates
- Ability to graph complex functions in the complex plane
- Ability to graph parametric equations in 3D
- Ability to graph vector fields
- Ability to display equations of asymptotes or tangents on polar graphs
- Ability to change the window/domain and range of the graph
- Ability to change the frequency of points calculated
III
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Quick Graph
- Advanced Features$1.99
- Buy Us a Coffee$1.99
III
No in-app purchases
