# Structured Flow vs Dioptra

The clearest difference is iOS requirement: Structured Flow at 15.0 against Dioptra's 17.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Structured Flow sells 2 in-app purchases, starting at $0.99 per 7 days and Dioptra sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Structured Flow ships an update weekly, Dioptra fortnightly. The most recent releases landed on October 28, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | Structured Flow | Dioptra |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Weekly** | Fortnightly |
| Size | 58 MB | 5 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Jorge Alves](https://appshunter.io/developer/1838093137) | [Zachary Griffin](https://appshunter.io/developer/1813803229) |

## What reviewers say

### Structured Flow

[App page](https://appshunter.io/ios/app/structured-flow-daily-planner/id6789644116)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Weekly | $0.99 | per 7 days |
| Premium Annual | $9.99 | per year |


### Dioptra

[App page](https://appshunter.io/ios/app/dioptra-glb-3d-model-viewer/id6812574588)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Small Tip | $0.99 | one-time |
| Tip | $1.99 | one-time |
| Generous Tip | $4.99 | one-time |


## Frequently asked questions

### Is Structured Flow free?

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

### Is Dioptra free?

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

### Do Structured Flow or Dioptra have ads?

Neither Structured Flow nor Dioptra shows ads.

### Which is updated more often, Structured Flow or Dioptra?

Structured Flow ships an update weekly, and Dioptra fortnightly. Most recently, Structured Flow was updated on October 28, 2026 and Dioptra on October 26, 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.*