# Obstac

> Obstac (iPhone/iPad app by Viet Truong Bao.)

- Source: https://appshunter.io/ios/app/obstac/id6763231670 (this page in markdown: same URL + `.md`)
- Developer: [Viet Truong Bao](https://appshunter.io/developer/1895224968)
- Category: Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 14.0 · 4 MB
- Languages: English
- Released: 2026-04-23
- Data updated: 2026-05-17
- User reviews in markdown: https://appshunter.io/ios/app/obstac/id6763231670/reviews.md

## What is Obstac?

A professional tool for mathematical algebraic topology.
In obstacle theory, users can choose the spatial type (CW complex, manifold, suspension, product), adjust the homology group dimension (n=1 to 10), and calculate the obstacle category ⁿ⁺¹ (X; π ₙ (F)) in H. The Postnikov Tower Construction module provides interactive tower visualization with color coding layers, customizable base spaces, k-invariant selection, and adjustable stages from 1 to 5.
Classification space BG feature calculation homology H ⁿ (X; A) is applicable to various group types (including cyclic groups, product groups, finite groups, and Lie groups) of orders 0-8. Homotopy Lifting Analysis provides fiber visualization, supporting Serre, Hurewicz, and quasi fiber types, as well as path lift characteristic analysis.
Users can explore Moore Postnikov decomposition using visual factor chains and long exact sequences, and generate Eilenberg MacLane space K (π, n）。 The application also includes a built-in feedback system for user input.


## Version history (last 2 releases)

### 1.0.1 — 2026-05-02

some bugs fixed

### 1.0 — 2026-04-23

No release notes.

## Related topics

[cohomologyclx](https://appshunter.io/ios/topics/cohomologyclx)

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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 2026-05-17.*