# プリペイドSIM屋さん vs Letter

The clearest difference is in-app purchases: プリペイドSIM屋さん at none against Letter's 6. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Letter sells 6 one-off in-app purchases. プリペイドSIM屋さん asks for nothing beyond the download.

プリペイドSIM屋さん ships an update every 9 days, Letter every 5 days. The most recent releases landed on October 31, 2026 and November 10, 2026 respectively.

## The numbers

| Metric | プリペイドSIM屋さん | Letter |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 9 days | **Every 5 days** |
| Size | 26 MB | 70 MB |
| Requires iOS | 17.0 | **16.4** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 17+ | 4+ |
| Developer | [LinkMobile k.k](https://appshunter.io/developer/1896739818) | [VUNYO](https://appshunter.io/developer/1768332147) |

## What reviewers say

### プリペイドSIM屋さん

[App page](https://appshunter.io/ios/app/sim/id6770400655)

**In-app purchases:** none


### Letter

[App page](https://appshunter.io/ios/app/letter-write-send-post-mail/id6786452084)

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Credit | $1.99 | one-time |
| Credit | $4.99 | one-time |
| Credit | $6.99 | one-time |
| Credit | $9.99 | one-time |
| Credit | $19.99 | one-time |
| Credit | $49.99 | one-time |


## Frequently asked questions

### Is プリペイドSIM屋さん free?

プリペイドSIM屋さん is free to download, with no in-app purchases.

### Is Letter free?

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

### Do プリペイドSIM屋さん or Letter have ads?

Neither プリペイドSIM屋さん nor Letter shows ads.

### Which is updated more often, プリペイドSIM屋さん or Letter?

プリペイドSIM屋さん ships an update every 9 days, and Letter every 5 days. Most recently, プリペイドSIM屋さん was updated on October 31, 2026 and Letter on November 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.*