# Nuki Smart Lock vs Simon iO

The clearest difference is review sentiment: Nuki Smart Lock at 90% against Simon iO's 29%. Nuki Smart Lock also leads on rating (4.7 vs 1.0) and ads (none vs shown). Simon iO's advantage is iOS requirement (14.0 vs 16.0). On price, 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.

Nuki Smart Lock holds the better App Store score, 4.7 against 1.0. That said, the two scores are not equally well evidenced: Nuki Smart Lock has 515 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 90% of Nuki Smart Lock's written reviews are positive against 29% of Simon iO's.

Nuki Smart Lock ships an update every 3 weeks, Simon iO every 3 months. The most recent releases landed on October 20, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | Nuki Smart Lock | Simon iO |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (515 ratings)](https://appshunter.io/ios/app/nuki-smart-lock/id1044998081/reviews)** | [1.0 (1 ratings)](https://appshunter.io/ios/app/simon-io/id1477805916/reviews) |
| Number of ratings | **515** | 1 |
| Positive reviews | **90.2% of reviews** | 28.6% of reviews |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Every 3 weeks** | Every 3 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 298 MB | 91 MB |
| Requires iOS | 16.0 | **14.0** |
| Devices | iPhone, Apple Watch | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Nuki Home Solutions GmbH](https://appshunter.io/developer/966180578) | [Simon](https://appshunter.io/developer/531284305) |

## What reviewers say

### Nuki Smart Lock

[App page](https://appshunter.io/ios/app/nuki-smart-lock/id1044998081)

Transform your smartphone into a secure digital key for your home. Grant and manage access for family and friends, and monitor who enters and when. Enjoy convenient features like automatic unlocking and locking, with easy DIY installation and smart home integration.

**Highlights:** Turn phone into a key, Share access permissions, Activity log, Auto Unlock/Lock, Night Mode, Smart Home integration, DIY installation

**Features:** Apple Watch app

**In-app purchases:** none

**What reviewers like**

- 🚀 Easy to use
- 🔒 Secure
- 👍 Convenient features
- 🔑 Works with existing locks
- ⚙️ Customizable settings

**What reviewers complain about**

- 🐛 Occasional connectivity issues
- 🔋 Battery life concerns
- 🕰️ Slow response times
- 🤔 Confusing UI/UX

**Reported bugs**

- Unreliable geofencing
- Inconsistent unlock/lock functionality
- Buggy app updates

**Requested features**

- Improved battery status monitoring
- Customizable auto-lock/unlock timers
- Stronger HomeKit/Alexa integration
- Ability to create/share access codes


### Simon iO

[App page](https://appshunter.io/ios/app/simon-io/id1477805916)

Control your smart home devices, including lights and blinds, from anywhere. Receive notifications, schedule routines, and customize device functionalities like lighting levels and power control. This app enhances your iO universe with a world of possibilities.

**Highlights:** Configure iO devices and experiences, Control lights and blinds, Receive notifications, Schedule routines, Adjust lighting levels, Power control for devices

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Nuki Smart Lock free?

Nuki Smart Lock is free to download, with no in-app purchases.

### Is Simon iO free?

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

### Which has better reviews, Nuki Smart Lock or Simon iO?

Nuki Smart Lock is rated higher. Nuki Smart Lock averages 4.7 out of 5 from 515 ratings, while Simon iO averages 1.0 from 1 ratings.

### Do Nuki Smart Lock or Simon iO have ads?

Simon iO shows ads; Nuki Smart Lock does not.

### Which is updated more often, Nuki Smart Lock or Simon iO?

Nuki Smart Lock ships an update every 3 weeks, and Simon iO every 3 months. Most recently, Nuki Smart Lock was updated on October 20, 2026 and Simon iO on October 12, 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.*