# Pearl Diver HD vs Stack Up

The clearest difference is rating: Stack Up at 5.0 against Pearl Diver HD's 1.5. Stack Up also leads on update cadence (every 2 months vs every 20 months) and review sentiment (100% vs 71%). On price, ads, in-app purchases and monetization model there is nothing between them.

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

Stack Up holds the better App Store score, 5.0 against 1.5. Both are backed by a comparable volume of ratings — 2 and 6 respectively. Written reviews point the same way: 71% of Pearl Diver HD's written reviews are positive against 100% of Stack Up's.

Pearl Diver HD ships an update every 20 months, Stack Up every 2 months. The most recent releases landed on November 1, 2026 and November 6, 2026 respectively.

## The numbers

| Metric | Pearl Diver HD | Stack Up |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.5 (2 ratings)](https://appshunter.io/ios/app/pearl-diver-hd/id364617763/reviews) | **[5.0 (6 ratings)](https://appshunter.io/ios/app/stack-up-stack-items-bottom-up-to-build-a-tower/id1135865797/reviews)** |
| Number of ratings | 2 | **6** |
| Positive reviews | 71.4% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 20 months | **Every 2 months** |
| Monetization | Free | Free |
| Size | 28 MB | 65 MB |
| Requires iOS | 17.6 | **7.0** |
| Devices | **iPhone, iPad** | iPad |
| Age rating | 4+ | 4+ |
| Developer | [New Mexico State University Board of Regents](https://appshunter.io/developer/337567846) | [STEP BY STEP](https://appshunter.io/developer/961412234) |

## What reviewers say

### Pearl Diver HD

[App page](https://appshunter.io/ios/app/pearl-diver-hd/id364617763)

Dive into the ocean depths to master the number line, including fractions and decimals, by collecting pearls. This game is designed by educators to align with Common Core standards for grades 3-8.

**Highlights:** Number line mastery, Fractions and decimals, Common Core standards alignment, Progress tracking, Educational game design, Pearl collection gameplay

**Features:** macOS Compatibility

**In-app purchases:** none


### Stack Up

[App page](https://appshunter.io/ios/app/stack-up-stack-items-bottom-up-to-build-a-tower/id1135865797)

This educational app helps children aged 2.5 and up learn to arrange items by width. It fosters visual perception and primary math skills through engaging, simple activities. Designed for young learners, it avoids distractions and offers progress tracking for educators.

**Highlights:** Arranging items by width, Develops visual perception, Teaches primary math concepts, Progress tracking for educators, Safe for children, Simple and intuitive design

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Pearl Diver HD free?

Pearl Diver HD is free to download, with no in-app purchases.

### Is Stack Up free?

Stack Up is free to download, with no in-app purchases.

### Which has better reviews, Pearl Diver HD or Stack Up?

Stack Up is rated higher. Pearl Diver HD averages 1.5 out of 5 from 2 ratings, while Stack Up averages 5.0 from 6 ratings.

### Do Pearl Diver HD or Stack Up have ads?

Neither Pearl Diver HD nor Stack Up shows ads.

### Which is updated more often, Pearl Diver HD or Stack Up?

Pearl Diver HD ships an update every 20 months, and Stack Up every 2 months. Most recently, Pearl Diver HD was updated on November 1, 2026 and Stack Up on November 6, 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.*