# AlterLock vs SIGEYI

The clearest difference is in-app purchases: SIGEYI at none against AlterLock's 2. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. AlterLock sells 2 in-app purchases, starting at $3.99 per month. SIGEYI asks for nothing beyond the download.

AlterLock ships an update every 2 months, SIGEYI every 3 months. The most recent releases landed on September 22, 2026 and September 15, 2026 respectively.

## The numbers

| Metric | AlterLock | SIGEYI |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.7 (3 ratings)](https://appshunter.io/ios/app/alterlock/id1418389534/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 33.3% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 3 months |
| Monetization | Free with in-app purchases | — |
| Size | 87 MB | 48 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [NEXTSCAPE INC.](https://appshunter.io/developer/434362565) | [Sigeyi Technology (Guangzhou) Co., Ltd.](https://appshunter.io/developer/1736871513) |

## What reviewers say

### AlterLock

[App page](https://appshunter.io/ios/app/alterlock/id1418389534)

This app pairs with a theft prevention device to monitor your vehicle. It offers loud alarms, smartphone notifications, and GPS tracking to deter theft and provide location updates. Manage vehicle details, device settings, and track your assets with peace of mind.

**Highlights:** Movement-detection alarm, Smartphone notifications, Independent communication, Advanced GPS tracking, Vehicle registration, Device settings adjustment, Map-based location history

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Plan | $3.99 | per month |
| Annual Plan | $39.95 | per year |


### SIGEYI

[App page](https://appshunter.io/ios/app/sigeyi/id1449815400)

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

**In-app purchases:** none


## Frequently asked questions

### Is AlterLock free?

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

### Is SIGEYI free?

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

### Do AlterLock or SIGEYI have ads?

Neither AlterLock nor SIGEYI shows ads.

### Which is updated more often, AlterLock or SIGEYI?

AlterLock ships an update every 2 months, and SIGEYI every 3 months. Most recently, AlterLock was updated on September 22, 2026 and SIGEYI on September 15, 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.*