Nuki Smart Lock vs Simon iO
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Nuki Smart Lock
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.
- Turn phone into a key
- Share access permissions
- Activity log
- Auto Unlock/Lock
- Night Mode
- Smart Home integration
- DIY installation
Read full descriptionHide full description
Turn your iPhone into a key – with Nuki Nuki: The retrofittable, smart door lock. Innovated in Austria – manufactured in Europe. APP REPLACES KEYS Turn your smart devices into keys. With the free Nuki app, you can open your door with your iPhone or your Apple Watch. Open the door with just one click, even remotely. SHARING KEYS Share access permissions with the Nuki app. Simple and secure. You decide who has access. With the activity log you always know who unlocked your door and when. SMART FEATURES Auto Unlock: Your door opens automatically when you come home. Auto Lock: Automatic locking, form maximum security. Night Mode: Activate various safety features during the night. Customize the night mode to your needs. SMART HOME INTEGRATIONS Easy and fast integration into your existing Smart Home. Thanks to Matter Nuki Smart Locks are compatible with most Smart Home systems. Matter ensures an easy and fast integration. EASY DIY INSTALLATION You can install the Nuki Smart Lock yourself within a few minutes. The Nuki app supports you with a step-by-step guide. See if Nuki is compatible with your door here: www.nuki.io/check SMART ACCESSOIRES The Nuki ecosystem offers you a variety of accessoires. Open fast via fingerprint or entry code with the Nuki Keypad 2 or simple and easy via button with the Nuki Fob. No smartphone needed. Get your Smart Lock now directly in our online shop: https://shop.nuki.io/ We’d love to hear from you. If you have questions about Nuki products please contact us at contact@nuki.io, or visit us on social media.
Simon iO
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.
- Configure iO devices and experiences
- Control lights and blinds
- Receive notifications
- Schedule routines
- Adjust lighting levels
- Power control for devices
Read full descriptionHide full description
* [IMPORTANT] This application is only compatible with the new HUB PRO iO (installations from 2020) The Simon iO app allows you to easily configure this entire new iO universe: from the iO devices, to the desired experiences. Experiences that you can change as many times as you want, since the process is really simple. Control lights, blinds and weather from inside and outside the home, receive notifications and schedule schedules will also be possible from the Simon iO app. Increasing the functionalities of your iO devices such as soft lighting of lights, regulation levels, beacons, power off delay and power control will also be possible. In short, a world of possibilities that are now at your fingertips. For further information please contact with: sat@simon.es
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | Nuki Smart Lock | Simon iO |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (515 ratings) — better | 1.0 (1 ratings) |
| Positive reviews | 90.2% of reviews — better | 28.6% of reviews |
| Number of ratings | 515 — better | 1 |
| Update frequency | Every 3 weeks — better | Every 3 months |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, Apple Watch | iPhone, iPod |
| Requires iOS | 16.0 | 14.0 — better |
| Further details — not scored | ||
| Size | 298 MB | 91 MB |
| Age rating | 4+ | 4+ |
| Developer | Nuki Home Solutions GmbH | Simon |
Customer experience
Nuki Smart Lock
Simon iO
Bugs and requests
Nuki Smart Lock
Reported bugs
3 issues- Unreliable geofencing
- Inconsistent unlock/lock functionality
- Buggy app updates
Requested features
4 requests- Improved battery status monitoring
- Customizable auto-lock/unlock timers
- Stronger HomeKit/Alexa integration
- Ability to create/share access codes
Simon iO
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Nuki Smart Lock
No in-app purchases
Simon iO
No in-app purchases
Questions
Is Nuki Smart Lock free?
Is Simon iO free?
Which has better reviews, Nuki Smart Lock or Simon iO?
Do Nuki Smart Lock or Simon iO have ads?
Which is updated more often, Nuki Smart Lock or Simon iO?
Other comparisons
