# 超シンプル 書籍検索 vs Letterly

超シンプル 書籍検索 and Letterly are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

超シンプル 書籍検索 ships an update weekly, Letterly every 10 days. The most recent releases landed on November 3, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | 超シンプル 書籍検索 | Letterly |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (4 ratings)](https://appshunter.io/ios/app/letterly-anonymous-letters/id6747300343/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | **Weekly** | Every 10 days |
| Monetization | — | Ad-supported |
| Size | 20 MB | 21 MB |
| Requires iOS | **16.0** | 17.6 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 9+ | 17+ |
| Developer | [shimizu syoki](https://appshunter.io/developer/1650725937) | [Dusonn Dubaal](https://appshunter.io/developer/1820687291) |

## What reviewers say

### 超シンプル 書籍検索

[App page](https://appshunter.io/ios/app/id6446250091)

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

**In-app purchases:** none


### Letterly

[App page](https://appshunter.io/ios/app/letterly-anonymous-letters/id6747300343)

Connect with others globally by anonymously sharing your thoughts and feelings. Receive a daily letter of empathy and comfort, and open up to someone new each day.

**Highlights:** Anonymous letter writing, Global connection, Daily empathy letters, Share feelings and thoughts, Find comfort and support

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

**In-app purchases:** none


## Frequently asked questions

### Is 超シンプル 書籍検索 free?

超シンプル 書籍検索 is free to download, with no in-app purchases.

### Is Letterly free?

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

### Do 超シンプル 書籍検索 or Letterly have ads?

Both 超シンプル 書籍検索 and Letterly show ads.

### Which is updated more often, 超シンプル 書籍検索 or Letterly?

超シンプル 書籍検索 ships an update weekly, and Letterly every 10 days. Most recently, 超シンプル 書籍検索 was updated on November 3, 2026 and Letterly on November 5, 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.*