# OTN vs SixDo

The clearest difference is ads: SixDo at none against OTN's shown. OTN's advantage is update cadence (every 3 days vs every 3 weeks) and device support (3 vs 1). On price, in-app purchases and iOS requirement there is nothing between them.

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

OTN ships an update every 3 days, SixDo every 3 weeks. The most recent releases landed on October 24, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | OTN | SixDo |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 3 days** | Every 3 weeks |
| Size | 6 MB | 32 MB |
| Requires iOS | 17.0 | **16.0** |
| Devices | **iPhone, iPad, Mac** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [SeokHui Lee](https://appshunter.io/developer/1129769874) | [mami hara](https://appshunter.io/developer/6792413290) |

## What reviewers say

### OTN

[App page](https://appshunter.io/ios/app/otn-one-time-note/id6793473020)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OTN Pro | $0.99 | one-time |


### SixDo

[App page](https://appshunter.io/ios/app/sixdo-ivy-lee-method-to-do/id6797027631)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SixDo Pro | $3.99 | one-time |


## Frequently asked questions

### Is OTN free?

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

### Is SixDo free?

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

### Do OTN or SixDo have ads?

OTN shows ads; SixDo does not.

### Which is updated more often, OTN or SixDo?

OTN ships an update every 3 days, and SixDo every 3 weeks. Most recently, OTN was updated on October 24, 2026 and SixDo 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.*