# S.i vs Couple Calendar

The clearest difference is in-app purchases: S.i at none against Couple Calendar's 1. S.i also leads on iOS requirement (13.0 vs 26.0). Couple Calendar's advantage is update cadence (every 6 days vs every 48 months). On price, ads and device support there is nothing between them.

Both are free to download. Couple Calendar sells 1 one-off in-app purchase. S.i asks for nothing beyond the download.

S.i ships an update every 48 months, Couple Calendar every 6 days. The most recent releases landed on September 12, 2026 and September 13, 2026 respectively.

## The numbers

| Metric | S.i | Couple Calendar |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 48 months | **Every 6 days** |
| Size | 3 MB | 31 MB |
| Requires iOS | **13.0** | 26.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [TATSUHIRO INOUE](https://appshunter.io/developer/1610301721) | [Takuro Yoshizawa](https://appshunter.io/developer/1839233118) |

## What reviewers say

### S.i

[App page](https://appshunter.io/ios/app/si/id1610301719)

**In-app purchases:** none


### Couple Calendar

[App page](https://appshunter.io/ios/app/couple-calendar-shared/id6760582483)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Koibito Calendar Premium | $6.99 | one-time |


## Frequently asked questions

### Is S.i free?

S.i is free to download, with no in-app purchases.

### Is Couple Calendar free?

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

### Do S.i or Couple Calendar have ads?

Neither S.i nor Couple Calendar shows ads.

### Which is updated more often, S.i or Couple Calendar?

S.i ships an update every 48 months, and Couple Calendar every 6 days. Most recently, S.i was updated on September 12, 2026 and Couple Calendar on September 13, 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.*