# SAJ vs smart LK

The clearest difference is update cadence: smart LK at monthly against SAJ's every 23 months. SAJ's advantage is iOS requirement (8.0 vs 11.0). On price, ads, in-app purchases and device support there is nothing between them.

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

SAJ ships an update every 23 months, smart LK monthly. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | SAJ | smart LK |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/smart-lk/id1492795311/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 23 months | **Monthly** |
| Monetization | — | Free |
| Size | 152 MB | 12 MB |
| Requires iOS | **8.0** | 11.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [SAJ Instrument Ab](https://appshunter.io/developer/962246290) | [libing yang](https://appshunter.io/developer/1435297539) |

## What reviewers say

### SAJ

[App page](https://appshunter.io/ios/app/saj-dms-calib/id962246291)

**Features:** macOS Compatibility

**In-app purchases:** none


### smart LK

[App page](https://appshunter.io/ios/app/smart-lk/id1492795311)

Control your smart lock remotely with this app. It supports unlocking via password and offers security alerts for brute-force attempts on fingerprint locks, ensuring property safety.

**Highlights:** Remote unlocking, Password lock support, Brute force crack alerts, Property safety notifications

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SAJ free?

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

### Is smart LK free?

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

### Do SAJ or smart LK have ads?

Neither SAJ nor smart LK shows ads.

### Which is updated more often, SAJ or smart LK?

SAJ ships an update every 23 months, and smart LK monthly. Most recently, SAJ was updated on November 1, 2026 and smart LK on November 3, 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.*