# Python Data Structures & Algo vs ShellRef

The clearest difference is price: Python Data Structures & Algo at Free against ShellRef's $0.99. ShellRef's advantage is update cadence (every 3 weeks vs every 2 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Python Data Structures & Algo is free to download; ShellRef costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Python Data Structures & Algo ships an update every 2 months, ShellRef every 3 weeks. The most recent releases landed on October 1, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Python Data Structures & Algo | ShellRef |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/shellref/id6759814118/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | — | Paid |
| Size | 17 MB | 19 MB |
| Requires iOS | **17.0** | 17.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [ALG Software Lab](https://appshunter.io/developer/1650561236) | [Andrew Bacon](https://appshunter.io/developer/1817531814) |

## What reviewers say

### Python Data Structures & Algo

[App page](https://appshunter.io/ios/app/python-data-structures-and-algo/id6757224683)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### ShellRef

[App page](https://appshunter.io/ios/app/shellref/id6759814118)

This app provides an offline reference for Bash, Zsh, and terminal editors, mimicking a retro technical manual. It's ideal for quickly looking up commands, syntax, and scripting practices without needing an internet connection. Features include search, bookmarks, and customizable display themes.

**Highlights:** Offline Bash and Zsh reference, Terminal editor guides (Nano, Vim, Emacs), Quick command lookup, Searchable content, Customizable themes, Adjustable text size, Bookmarks

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Python Data Structures & Algo free?

Python Data Structures & Algo is free to download, with no in-app purchases.

### Is ShellRef free?

ShellRef costs $0.99, with no in-app purchases.

### Do Python Data Structures & Algo or ShellRef have ads?

Neither Python Data Structures & Algo nor ShellRef shows ads.

### Which is updated more often, Python Data Structures & Algo or ShellRef?

Python Data Structures & Algo ships an update every 2 months, and ShellRef every 3 weeks. Most recently, Python Data Structures & Algo was updated on October 1, 2026 and ShellRef on October 2, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*