# iSometric 3D Form vs Modstack

The clearest difference is in-app purchases: iSometric 3D Form at none against Modstack's 1. Modstack's advantage is update cadence (every 8 days vs monthly). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Modstack sells 1 one-off in-app purchase. iSometric 3D Form asks for nothing beyond the download.

iSometric 3D Form ships an update monthly, Modstack every 8 days. The most recent releases landed on October 2, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | iSometric 3D Form | Modstack |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.2 (6 ratings)](https://appshunter.io/ios/app/isometric-3d-form/id1080191573/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 8 days** |
| Monetization | Free | — |
| Size | 279 MB | 30 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Jose Luis Lopez Alcazar](https://appshunter.io/developer/629942984) | [NovoBuild LLC](https://appshunter.io/developer/1784126512) |

## What reviewers say

### iSometric 3D Form

[App page](https://appshunter.io/ios/app/isometric-3d-form/id1080191573)

This game challenges players to assemble 3D geometric shapes by correctly aligning front, left, and top views. It offers numerous levels with increasing difficulty, requiring careful observation to form the isometric figures.

**Highlights:** Multiple difficulty levels, Form 3D figures, Use front, left, and top views, Hidden line challenges, All levels are free

**Features:** macOS Compatibility

**In-app purchases:** none


### Modstack

[App page](https://appshunter.io/ios/app/modstack-programming-puzzle/id6803866356)

**Features:** Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Full Modstack | $3.99 | one-time |


## Frequently asked questions

### Is iSometric 3D Form free?

iSometric 3D Form is free to download, with no in-app purchases.

### Is Modstack free?

Modstack is free to download, with in-app purchases available.

### Do iSometric 3D Form or Modstack have ads?

Neither iSometric 3D Form nor Modstack shows ads.

### Which is updated more often, iSometric 3D Form or Modstack?

iSometric 3D Form ships an update monthly, and Modstack every 8 days. Most recently, iSometric 3D Form was updated on October 2, 2026 and Modstack 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.*