# Ondi vs DdongDal

The clearest difference is ads: Ondi at none against DdongDal's shown. DdongDal's advantage is iOS requirement (15.0 vs 17.0). On price, update cadence, in-app purchases and device support there is nothing between them.

Both are free to download. Ondi sells 1 one-off in-app purchase and DdongDal sells 4 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on October 28, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Ondi | DdongDal |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | Weekly | Weekly |
| Size | 10 MB | 43 MB |
| Requires iOS | 17.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [Blue Flame Games](https://appshunter.io/developer/523824138) | [HyeIn Kim](https://appshunter.io/developer/6792473249) |

## What reviewers say

### Ondi

[App page](https://appshunter.io/ios/app/ondi-private-period-tracker/id6760896784)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Cyla Premium | $7.99 | one-time |


### DdongDal

[App page](https://appshunter.io/ios/app/ddongdal/id6792473247)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Food Stickers A | $0.99 | one-time |
| Food Stickers B | $0.99 | one-time |
| Workout Stickers | $0.99 | one-time |
| Remove Ads | $2.99 | one-time |


## Frequently asked questions

### Is Ondi free?

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

### Is DdongDal free?

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

### Do Ondi or DdongDal have ads?

DdongDal shows ads; Ondi does not.

### Which is updated more often, Ondi or DdongDal?

Ondi ships an update weekly, and DdongDal weekly. Most recently, Ondi was updated on October 28, 2026 and DdongDal on October 31, 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.*