# scCalendarHD（スクロールカレンダーHD） vs YYサイレンアラート

The clearest difference is review sentiment: YYサイレンアラート at 50% against scCalendarHD（スクロールカレンダーHD）'s 0%. YYサイレンアラート also leads on price (Free vs $0.99) and update cadence (monthly vs every 3 months). scCalendarHD（スクロールカレンダーHD）'s advantage is iOS requirement (9.0 vs 15.0). On ads and in-app purchases there is nothing between them.

YYサイレンアラート is free to download; scCalendarHD（スクロールカレンダーHD） costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

scCalendarHD（スクロールカレンダーHD） ships an update every 3 months, YYサイレンアラート monthly. The most recent releases landed on October 20, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | scCalendarHD（スクロールカレンダーHD） | YYサイレンアラート |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Positive reviews | 0.0% of reviews | **50.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | Paid | **Free** |
| Size | 10 MB | 6 MB |
| Requires iOS | **9.0** | 15.0 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Keietsu Yasuhara](https://appshunter.io/developer/378538320) | [株式会社エクォス・リサーチ](https://appshunter.io/developer/1483010608) |

## What reviewers say

### scCalendarHD（スクロールカレンダーHD）

[App page](https://appshunter.io/ios/app/sccalendarhdhd/id396296664)

A calendar app that allows for quick scrolling and viewing of months. It displays the year in both Western and Japanese eras on the home screen and provides easy access to holidays, zodiac signs, age charts, and moon phases. Notes can be added and date information pasted.

**Highlights:** Quick scrolling calendar view, Western and Japanese era year display, Holidays, zodiac, age chart, moon phase, Rokuyo (Japanese calendar) list, Year list with date info copy, Year conversion table, Memo field for notes and pasting

**Features:** macOS Compatibility

**In-app purchases:** none


### YYサイレンアラート

[App page](https://appshunter.io/ios/app/yy/id6450823634)

This utility app visualizes important sounds like sirens and alarms, alerting users through visual cues and vibrations. It helps individuals who have difficulty hearing these sounds or want to be more aware of their auditory environment. The app detects various sounds, from emergency vehicles to everyday noises.

**Highlights:** Visualizes siren sounds, Alerts via display and vibration, Detects emergency vehicle sounds, Recognizes car horns and bicycle bells, Identifies fire alarms and intercoms, Visualizes speech, music, and breaking glass sounds

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

**In-app purchases:** none


## Frequently asked questions

### Is scCalendarHD（スクロールカレンダーHD） free?

scCalendarHD（スクロールカレンダーHD） costs $0.99, with no in-app purchases.

### Is YYサイレンアラート free?

YYサイレンアラート is free to download, with no in-app purchases.

### Do scCalendarHD（スクロールカレンダーHD） or YYサイレンアラート have ads?

Neither scCalendarHD（スクロールカレンダーHD） nor YYサイレンアラート shows ads.

### Which is updated more often, scCalendarHD（スクロールカレンダーHD） or YYサイレンアラート?

scCalendarHD（スクロールカレンダーHD） ships an update every 3 months, and YYサイレンアラート monthly. Most recently, scCalendarHD（スクロールカレンダーHD） was updated on October 20, 2026 and YYサイレンアラート on October 10, 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.*