# MobileKey vs BuildSec 4.0

MobileKey and BuildSec 4.0 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.

MobileKey ships an update every 3 months, BuildSec 4.0 every 2 months. The most recent releases landed on September 10, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | MobileKey | BuildSec 4.0 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/mobilekey/id1231074427/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 32.3% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 months** |
| Monetization | Free | — |
| Size | 49 MB | 204 MB |
| Requires iOS | **15.3** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [SimonsVoss Technologies GmbH](https://appshunter.io/developer/1141846652) | [Telenot Electronic GmbH](https://appshunter.io/developer/401623741) |

## What reviewers say

### MobileKey

[App page](https://appshunter.io/ios/app/mobilekey/id1231074427)

Manage door statuses, grant remote access, and send digital keys to friends. Receive messages from event management and view access lists. Secure actions with Touch ID.

**Highlights:** Door status overview, Remote door openings, Send digital keys (Key4Friends), View access lists, Receive event management messages, Touch ID security

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

**In-app purchases:** none


### BuildSec 4.0

[App page](https://appshunter.io/ios/app/buildsec-40/id1472711329)

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

**In-app purchases:** none


## Frequently asked questions

### Is MobileKey free?

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

### Is BuildSec 4.0 free?

BuildSec 4.0 is free to download, with no in-app purchases.

### Do MobileKey or BuildSec 4.0 have ads?

Neither MobileKey nor BuildSec 4.0 shows ads.

### Which is updated more often, MobileKey or BuildSec 4.0?

MobileKey ships an update every 3 months, and BuildSec 4.0 every 2 months. Most recently, MobileKey was updated on September 10, 2026 and BuildSec 4.0 on September 19, 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.*