# Self SDG vs DuelEng

The clearest difference is in-app purchases: Self SDG at none against DuelEng's 2. Self SDG also leads on ads (none vs shown). DuelEng's advantage is update cadence (every 8 days vs every 4 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. DuelEng sells 2 in-app purchases, starting at $3.99 per month. Self SDG asks for nothing beyond the download.

Self SDG ships an update every 4 months, DuelEng every 8 days. The most recent releases landed on October 2, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Self SDG | DuelEng |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 4 months | **Every 8 days** |
| Size | 81 MB | 28 MB |
| Requires iOS | **15.6** | 16.6 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 17+ | 12+ |
| Developer | [Rafael Montilla Castillo](https://appshunter.io/developer/1846362390) | [Erdener YAVUZ](https://appshunter.io/developer/1874921189) |

## What reviewers say

### Self SDG

[App page](https://appshunter.io/ios/app/self-sdg/id6754036312)

**Features:** macOS Compatibility

**In-app purchases:** none


### DuelEng

[App page](https://appshunter.io/ios/app/dueleng/id6782185127)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| DuelEng Premium Monthly | $3.99 | per month |
| DuelEng Premium Yearly | $39.99 | per year |


## Frequently asked questions

### Is Self SDG free?

Self SDG is free to download, with no in-app purchases.

### Is DuelEng free?

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

### Do Self SDG or DuelEng have ads?

DuelEng shows ads; Self SDG does not.

### Which is updated more often, Self SDG or DuelEng?

Self SDG ships an update every 4 months, and DuelEng every 8 days. Most recently, Self SDG was updated on October 2, 2026 and DuelEng on October 9, 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.*