# Otter Curiosity vs HFI One

The clearest difference is in-app purchases: HFI One at none against Otter Curiosity's 2. HFI One also leads on update cadence (every 3 days vs every 2 weeks). Otter Curiosity's advantage is iOS requirement (15.0 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. Otter Curiosity sells 2 in-app purchases, starting at $7.99 per month. HFI One asks for nothing beyond the download.

Otter Curiosity ships an update every 2 weeks, HFI One every 3 days. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Otter Curiosity | HFI One |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 3 days** |
| Size | 72 MB | 15 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Chang-Shen Wu](https://appshunter.io/developer/1687362208) | [恩澄 许](https://appshunter.io/developer/1888657735) |

## What reviewers say

### Otter Curiosity

[App page](https://appshunter.io/ios/app/otter-curiosity/id6449002669)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Otter Member | $7.99 | per month |
| 好奇海獺貝殼 | $5.99 | one-time |


### HFI One

[App page](https://appshunter.io/ios/app/hfi-one/id6777857576)

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

**In-app purchases:** none


## Frequently asked questions

### Is Otter Curiosity free?

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

### Is HFI One free?

HFI One is free to download, with no in-app purchases.

### Do Otter Curiosity or HFI One have ads?

Neither Otter Curiosity nor HFI One shows ads.

### Which is updated more often, Otter Curiosity or HFI One?

Otter Curiosity ships an update every 2 weeks, and HFI One every 3 days. Most recently, Otter Curiosity was updated on November 3, 2026 and HFI One 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.*