# Structural Lines vs Stacy

The clearest difference is in-app purchases: Structural Lines at none against Stacy's 2. Stacy's advantage is update cadence (weekly vs every 2 months) and device support (4 vs 2). On price, ads and iOS requirement there is nothing between them.

Both are free to download. Stacy sells 2 in-app purchases, starting at $7.99 per month. Structural Lines asks for nothing beyond the download.

Structural Lines ships an update every 2 months, Stacy weekly. The most recent releases landed on September 16, 2026 and September 15, 2026 respectively.

## The numbers

| Metric | Structural Lines | Stacy |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Weekly** |
| Size | 56 MB | 35 MB |
| Requires iOS | 16.1 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Efficient Foundations Pty Ltd](https://appshunter.io/developer/1047597104) | [Sadullah Dinc](https://appshunter.io/developer/1896056348) |

## What reviewers say

### Structural Lines

[App page](https://appshunter.io/ios/app/structural-lines/id1425830779)

**Features:** macOS Compatibility

**In-app purchases:** none


### Stacy

[App page](https://appshunter.io/ios/app/stacy-ai-notes-and-whiteboard/id6789486650)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Stacy Pro (Monthly) | $7.99 | per month |
| Stacy Pro (Yearly) | $79.99 | per year |


## Frequently asked questions

### Is Structural Lines free?

Structural Lines is free to download, with no in-app purchases.

### Is Stacy free?

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

### Do Structural Lines or Stacy have ads?

Neither Structural Lines nor Stacy shows ads.

### Which is updated more often, Structural Lines or Stacy?

Structural Lines ships an update every 2 months, and Stacy weekly. Most recently, Structural Lines was updated on September 16, 2026 and Stacy on September 15, 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.*