# GridGrade — A real power-flow solver

> A real power-flow solver (iPhone/iPad app by Joshua Roberts.)

- Source: https://appshunter.io/ios/app/gridgrade/id6801503656 (this page in markdown: same URL + `.md`)
- Developer: [Joshua Roberts](https://appshunter.io/developer/6775962324)
- Category: Education, Reference
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 26.0 · 2 MB
- Languages: American English
- Released: 2026-09-03
- Data updated: 2026-09-06
- User reviews in markdown: https://appshunter.io/ios/app/gridgrade/id6801503656/reviews.md

## What is GridGrade?

GridGrade is a power-systems education app built on a real AC/DC power-flow solver — not a
simplified toy, the same Newton-Raphson math used to operate real electrical grids.

Load a scenario — from a hand-built 2-bus tutorial up to real published benchmark cases used to
validate power-flow software since 1962 (IEEE 14-bus, IEEE 30-bus) and the classic 3-machine
WSCC 9-bus system — and see it solved for real: every bus voltage and line flow is computed, not
looked up. Run N-1 contingency screening (the industry-standard "what if this one line failed
right now?" test) across every line at once. Then pick a line yourself and simulate it overloading
or going down completely, and watch the real trip logic — not a scripted animation — decide what
happens next, including whether it cascades into a second failure.

Build your own grid from scratch in a freeform topology editor, using the exact same solver every
built-in scenario runs on.

THREE READING LEVELS, ONE APP
Switch between Technical (real terminology — per-unit, voltage angle, N-1 security), Plain-language
(the same concepts in everyday words), and Child (a genuinely simpler experience for kids just
starting to explore how electricity moves — free tutorials only, no jargon).

WHAT'S FREE
Four tutorial scenarios, the full N-1 and cascade-simulation toolkit, and every reading level —
no account, no ads, no subscription.

WHAT UNLOCKS WITH ONE PURCHASE ($12.99, one time, no subscription)
The three real published benchmark cases (WSCC 9-bus, IEEE 14-bus, IEEE 30-bus — including real
transformer taps and shunt capacitors) and the freeform topology editor, so you can build and
solve your own grids.

WHO IT'S FOR
Power-systems and electrical-engineering students, utility-adjacent hobbyists, and anyone curious
how the grid that powers modern life actually works under load.

No account. No ads. Solver honesty is the whole point — nothing here is faked or approximated.

Privacy Policy: https://zavolagroup.com/gridlab/privacy
Support: https://zavolagroup.com/gridlab/support

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| GridGrade Full Unlock | $12.99 | one-time |



## Version history (last 1 release)

### 1.0.0 — 2026-09-03

No release notes.

## More apps by Joshua Roberts

- [Progresa](https://appshunter.io/ios/app/progresa/id6775962322)
- [PainPal - Endometriosis Sleuth](https://appshunter.io/ios/app/painpal-endometriosis-sleuth/id6775973529)
- [GridOp](https://appshunter.io/ios/app/gridop/id6792000919)
- [Gantix: Project Planner](https://appshunter.io/ios/app/gantix-project-planner/id6794028048)

All apps by Joshua Roberts: https://appshunter.io/developer/6775962324

---

*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 2026-09-06.*