# P.S. 21 Staten Island vs Multitape Turing Machine

The clearest difference is update cadence: P.S. 21 Staten Island at every 2 months against Multitape Turing Machine's every 8 months. P.S. 21 Staten Island also leads on ratings volume (3 vs 1). On price, rating, review sentiment and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for P.S. 21 Staten Island against 5.0 for Multitape Turing Machine. Both are backed by a comparable volume of ratings — 3 and 1 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

P.S. 21 Staten Island ships an update every 2 months, Multitape Turing Machine every 8 months. The most recent releases landed on October 20, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | P.S. 21 Staten Island | Multitape Turing Machine |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (3 ratings)](https://appshunter.io/ios/app/ps-21-staten-island/id1508040294/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/multitape-turing-machine/id6443568065/reviews) |
| Number of ratings | **3** | 1 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 8 months |
| Monetization | Free | Free |
| Size | 236 MB | 2 MB |
| Requires iOS | **15.6** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Solved Education Consultancy, LLC](https://appshunter.io/developer/1506645558) | [Denis Mandych](https://appshunter.io/developer/1647227152) |

## What reviewers say

### P.S. 21 Staten Island

[App page](https://appshunter.io/ios/app/ps-21-staten-island/id1508040294)

This app provides students, families, and staff with a centralized hub for academic information, school events, and communication. It offers features like grade access, PTA updates, staff directories, and professional development resources, all within an intuitive interface with translation and accessibility options.

**Highlights:** Student academic access (grades, schedules), Family engagement (PTA, staff directory), Staff resources (PBIS, CTLE), Real-time push notifications, Consolidated social media feed, Calendar and event details, Multilingual translation and accessibility

**In-app purchases:** none


### Multitape Turing Machine

[App page](https://appshunter.io/ios/app/multitape-turing-machine/id6443568065)

This app simulates a mathematical model of computation, allowing users to explore how abstract machines manipulate symbols on a tape according to defined rules. It's a tool for understanding the fundamental principles of computer algorithms.

**Highlights:** Turing machine simulation, Symbol manipulation on tape, Abstract computation model, Algorithm understanding, State and head movement

**In-app purchases:** none


## Frequently asked questions

### Is P.S. 21 Staten Island free?

P.S. 21 Staten Island is free to download, with no in-app purchases.

### Is Multitape Turing Machine free?

Multitape Turing Machine is free to download, with no in-app purchases.

### Which has better reviews, P.S. 21 Staten Island or Multitape Turing Machine?

P.S. 21 Staten Island and Multitape Turing Machine are both rated 5.0 out of 5 on the App Store, from 3 and 1 ratings respectively.

### Do P.S. 21 Staten Island or Multitape Turing Machine have ads?

Neither P.S. 21 Staten Island nor Multitape Turing Machine shows ads.

### Which is updated more often, P.S. 21 Staten Island or Multitape Turing Machine?

P.S. 21 Staten Island ships an update every 2 months, and Multitape Turing Machine every 8 months. Most recently, P.S. 21 Staten Island was updated on October 20, 2026 and Multitape Turing Machine on October 10, 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.*