Knotspan: Topology Trials
Untangle topology by proof
$1.99 · Designed for iPad. Not verified for macOS.
Transform tangled diagrams with legal local moves while preserving what matters. Includes 60 trials, a daily route, and an interactive Invariant Notebook.
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.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
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.
The developer, Robert Corbin, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Robert Corbin
- Size
- 77.2 MB
- Category
- Puzzle
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Age Rating
4+
- 4+
- Copyright
- © 2026 Robert Corbin
