# SMARTアドレス帳 for Local Sync vs IIJ SmartKey

The clearest difference is in-app purchases: IIJ SmartKey at none against SMARTアドレス帳 for Local Sync's 1. IIJ SmartKey also leads on iOS requirement (12.0 vs 14.0). SMARTアドレス帳 for Local Sync's advantage is update cadence (every 2 months vs every 9 months). On price, review sentiment, ads and device support there is nothing between them.

Both are free to download. SMARTアドレス帳 for Local Sync sells 1 one-off in-app purchase. IIJ SmartKey asks for nothing beyond the download.

SMARTアドレス帳 for Local Sync ships an update every 2 months, IIJ SmartKey every 9 months. Both last shipped on November 1, 2026.

## The numbers

| Metric | SMARTアドレス帳 for Local Sync | IIJ SmartKey |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 7.8% of reviews | **10.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 9 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 8 MB | 19 MB |
| Requires iOS | 14.0 | **12.0** |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Neos Corporation](https://appshunter.io/developer/455598658) | [Internet Initiative Japan, Inc.](https://appshunter.io/developer/444664358) |

## What reviewers say

### SMARTアドレス帳 for Local Sync

[App page](https://appshunter.io/ios/app/smart-for-local-sync/id667792796)

This contact management app offers familiar features for organizing contacts, including group creation, bulk messaging, and birthday notifications. It allows for easy searching and management of your address book.

**Highlights:** Group creation and editing, Bulk email sending, Birthday notifications, Favorite contact filtering, Contact search by name, email, or number, Call history display

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 機能制限の解除 | $1.99 | one-time |


### IIJ SmartKey

[App page](https://appshunter.io/ios/app/iij-smartkey/id974476420)

This app generates one-time passwords for two-step verification, enhancing online security. It supports TOTP standards and offers slide authentication for convenient logins. Additional features include app locking and cross-device data backup.

**Highlights:** Generates TOTP one-time passwords, Supports slide authentication, App locking with Touch ID/passcode, Cross-device data backup, Compatible with Google Authenticator

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

**In-app purchases:** none


## Frequently asked questions

### Is SMARTアドレス帳 for Local Sync free?

SMARTアドレス帳 for Local Sync is free to download, with in-app purchases available.

### Is IIJ SmartKey free?

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

### Do SMARTアドレス帳 for Local Sync or IIJ SmartKey have ads?

Neither SMARTアドレス帳 for Local Sync nor IIJ SmartKey shows ads.

### Which is updated more often, SMARTアドレス帳 for Local Sync or IIJ SmartKey?

SMARTアドレス帳 for Local Sync ships an update every 2 months, and IIJ SmartKey every 9 months. Most recently, SMARTアドレス帳 for Local Sync was updated on November 1, 2026 and IIJ SmartKey on November 1, 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.*