# Knotspan: Topology Trials — Untangle topology by proof

> Untangle topology by proof (iPhone/iPad app by Robert Corbin.)

- Source: https://appshunter.io/ios/app/knotspan-topology-trials/id6793303237 (this page in markdown: same URL + `.md`)
- Developer: [Robert Corbin](https://appshunter.io/developer/1890247992)
- Category: Games, Puzzle, Strategy
- Price: $2.99
- Age rating: 4+
- Requires: iOS 17.0 · 74 MB
- Released: 2026-07-26
- Data updated: 2026-08-14
- User reviews in markdown: https://appshunter.io/ios/app/knotspan-topology-trials/id6793303237/reviews.md

## What is Knotspan?

Knotspan is an offline topology puzzle campaign about simplifying knot diagrams through legal local transformations.

Read crossing order, identify reducible structures, preserve orientation, and build a short sequence of committed moves. Sixty authored trials reward deliberate reduction, clean chains, and mastery rather than random dragging.

Campaign stars and best scores stay on this device. The illustrated fieldbook provides an offline reference for crossings, orientation, legal moves, scoring, and the visual language used by the puzzles.

The new Invariant Notebook turns the core decision into a measurable practice exercise. Balance crossing reduction against invariant stability, introduce an orientation reversal, and inspect legal-move confidence before returning to the campaign. A deterministic daily Reidemeister route provides a shared date-based challenge without an account or server.

Knotspan includes local achievements, haptic and high-contrast preferences, reduced-effects controls, Dynamic Type, VoiceOver labels, and iPhone and iPad layouts.

One paid download includes every trial and feature. There are no subscriptions, ads, in-app purchases, accounts, analytics SDKs, or remote unlocks.


## Version history (last 2 releases)

### 1.1 — 2026-07-28

Knotspan 1.1 adds new mastery tools:

- Added deterministic daily legal-move routes with extra constraints.
- Added the interactive Invariant Notebook for crossing reduction, invariant stability, orientation reversal, and legal-move confidence.
- Added local achievements and richer campaign progress.
- Added haptic, reduced-effects, high-contrast, and left-handed preferences.
- Improved compact-screen gameplay spacing.
- Expanded automated coverage for daily routes, scoring, achievements, and persistence.

### 1.0 — 2026-07-26

No release notes.

## More apps by Robert Corbin

- [Daily Word Journey](https://appshunter.io/ios/app/daily-word-journey/id6761548266)
- [Hush Secret Text](https://appshunter.io/ios/app/hush-secret-text/id6761658175)
- [Renew Guard](https://appshunter.io/ios/app/renew-guard/id6761755447)
- [Receipt to PDF](https://appshunter.io/ios/app/receipt-to-pdf/id6761782025)
- [Route Your Pay](https://appshunter.io/ios/app/route-your-pay/id6761783719)
- [Tip Arbiter](https://appshunter.io/ios/app/tip-arbiter/id6761786879)

All apps by Robert Corbin: https://appshunter.io/developer/1890247992

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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 2026-08-14.*