Comparison

KAERU vs ShareDiary（シェアダイアリー）

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head

About

KAERU

A private and secure chat app designed for two people. It allows for quick messaging with a single tap, eliminating the need for registration or authentication. Easily send important messages to your dearest person.

Highlights

Private and secure chat
One-tap message sending
No registration required
No SNS authentication
Designed for two people

Features

Read full description

This chat application lets you to message "I am going home now(I am on the way home)" to the most special(important / dearest / loving / favorite / closest) person in the easiest way Private and secure chat service Send message by one tap on sent history No registration No SNS Authentication It's easier than e-mail sending home! Attn:This application is designed for two people

About

ShareDiary（シェアダイアリー）

Features

Read full description

ShareDiary は複数の相手と日記を共有できる交換日記サービスです。家族や友だち、恋人など様々なシーンでご利用いただけます。公式サイト https://sharediary.konnyaku256.dev/ プライバシーポリシー https://sharediary.konnyaku256.dev/privacy-policy 利用規約 https://sharediary.konnyaku256.dev/terms-and-conditions [:mav: 1.6.1]

Screenshots

KAERU4 screens

ShareDiary（シェアダイアリー）4 screens

Verdict

The call

The clearest difference is ads: ShareDiary（シェアダイアリー） at none against KAERU's shown. KAERU's advantage is update cadence (monthly vs every 2 months) and iOS requirement (12.0 vs 15.6). On price, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

KAERU ships an update monthly, ShareDiary（シェアダイアリー） every 2 months. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

Scorecard3 real differences · 5 level

KAERU versus ShareDiary（シェアダイアリー）: the parameters behind the verdict, then further details
Parameter	KAERU	ShareDiary（シェアダイアリー）
Price	Free	Free
Positive reviews	75.0% of reviews	—
Update frequency	Monthly — better	Every 2 months
Ads	Yes	No — better
In-app purchases	No	No
Monetization	Ad-supported	—
Devices	iPhone, iPod	iPhone, iPad, iPod — better
Requires iOS	12.0 — better	15.6
Further details — not scored
Size	18 MB	32 MB
Age rating	4+	4+
Developer	Densuke Inc.	Shuntaro Shimada

In-app purchases

None

KAERU

No in-app purchases

None

ShareDiary（シェアダイアリー）

No in-app purchases

Questions

Is KAERU free?

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

Is ShareDiary（シェアダイアリー） free?

ShareDiary（シェアダイアリー） is free to download, with no in-app purchases.

Do KAERU or ShareDiary（シェアダイアリー） have ads?

KAERU shows ads; ShareDiary（シェアダイアリー） does not.

Which is updated more often, KAERU or ShareDiary（シェアダイアリー）?

KAERU ships an update monthly, and ShareDiary（シェアダイアリー） every 2 months. Most recently, KAERU was updated on November 2, 2026 and ShareDiary（シェアダイアリー） on November 3, 2026.