# SPEED: Engineering Scratchpad

> SPEED: Engineering Scratchpad (iPhone/iPad app by HYUNG MIN SON.)

- Source: https://appshunter.io/ios/app/speed-engineering-scratchpad/id6811684234 (this page in markdown: same URL + `.md`)
- Developer: [HYUNG MIN SON](https://appshunter.io/developer/6811684236)
- Category: Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 15.0 · 98 MB
- Released: 2026-09-17
- Data updated: 2026-09-21
- User reviews in markdown: https://appshunter.io/ios/app/speed-engineering-scratchpad/id6811684234/reviews.md

## What is SPEED?

It is an equation-based line-by-line interpreter where equations and results are displayed simultaneously. Variable names can be utilized and re-used. Array variable is allowed which enables iterative calculation. It is also equipped with CoolProp library and IAPWS-IF97 water property function. Last, it works on plain ASCII text files which can be read and shared easily with others.

Great for on-the-fly, simple to complex engineering calculations. Right companion for solving elementary to practical level engineering problems.

Following features are currently supported.

- Simple to complex arithmetic calculations
- Simultaneous display of equations and results
- Variable assignment based connected calculations
- Array variable supported
- 5 level depth repetition loop
- Text output (echo) manipulation
  - Paraview output of 3D voxel data
- 1D, 2D linear interpolation
- Plotting
  - 1D scatter plot
  - 2D heatmap plot
  - 3D isometric plot
  - Histogram
  - Pie chart
  - Bar chart
  - Box plot
  - Stem and leaf plot
- CoolProp fluid property functions
- IAPWS-IF97 light water property calculation
- Linear equation solver (A*x=b)
- Nonlinear solvers
  - Bisection method
  - Golden-section maximization method
  - Particle swarm optimization (PSO) method for minimization
- Extensive statistical functions
  - Various distribution functions
  - Check for normality
  - Transformation
  - Tolerance limit factor
  - Linear regression
- Extensive unit conversion factors
- Other useful functions


## Version history (last 1 release)

### 1.0.5 — 2026-09-17

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-21.*