# ZeroControl vs Sutro

The clearest difference is rating: ZeroControl at 4.5 against Sutro's 3.9. Sutro's advantage is ratings volume (175 vs 8) and update cadence (every 2 months vs every 4 months). On price, review sentiment, ads and in-app purchases there is nothing between them.

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

ZeroControl holds the better App Store score, 4.5 against 3.9. That said, the two scores are not equally well evidenced: Sutro has 175 ratings behind it against 8, so its average is the more settled of the two. Written reviews point the same way: 75% of ZeroControl's written reviews are positive against 73% of Sutro's.

ZeroControl ships an update every 4 months, Sutro every 2 months. The most recent releases landed on June 4, 2026 and June 10, 2026 respectively.

## The numbers

| Metric | ZeroControl | Sutro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (8 ratings)](https://appshunter.io/ios/app/zerocontrol/id1257005426/reviews)** | [3.9 (175 ratings)](https://appshunter.io/ios/app/sutro/id1439627399/reviews) |
| Number of ratings | 8 | **175** |
| Positive reviews | **75.0% of reviews** | 72.9% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | Free | Free |
| Size | 114 MB | 39 MB |
| Requires iOS | **12.0** | 12.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Qingdao Richmat Intelligence Technology Inc.](https://appshunter.io/developer/1814751082) | [Sutro Connect Inc](https://appshunter.io/developer/1439627398) |

## What reviewers say

### ZeroControl

[App page](https://appshunter.io/ios/app/zerocontrol/id1257005426)

Control your bed or sofa with your mobile device. This app offers the same functionality as dedicated HJH handsets for dual or single actuator applications.

**Highlights:** Mobile device control, Dual actuator support, Single actuator support, Replicates handset functions, For bed and sofa applications

**In-app purchases:** none


### Sutro

[App page](https://appshunter.io/ios/app/sutro/id1439627399)

Effortlessly manage your pool or spa water quality. This app works with a smart monitor to automatically track pH, free chlorine, alkalinity, and temperature, providing insights that make sense for optimal water conditions.

**Highlights:** Automatic water quality monitoring, pH tracking, Free chlorine measurement, Alkalinity tracking, Temperature monitoring, Seamless app integration

**In-app purchases:** none

**What reviewers like**

- 🚀 Easy to use
- 👍 Accurate water testing
- 💡 Helpful notifications and recommendations
- 🔒 Reliable customer support
- 🚀 Convenient pool monitoring

**What reviewers complain about**

- 🐛 Connectivity issues
- 🐛 Inaccurate readings
- 🐛 Buggy app performance
- 🔋 Expensive subscription
- 🐛 Setup difficulties

**Reported bugs**

- App crashes and freezes
- Disconnection issues with hub
- Calibration failures
- Inaccurate water chemistry readings

**Requested features**

- Measure total hardness and CYA
- Customizable notification settings
- Ability to cancel subscription easily
- Improved app stability and user experience


## Frequently asked questions

### Is ZeroControl free?

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

### Is Sutro free?

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

### Which has better reviews, ZeroControl or Sutro?

ZeroControl is rated higher. ZeroControl averages 4.5 out of 5 from 8 ratings, while Sutro averages 3.9 from 175 ratings.

### Do ZeroControl or Sutro have ads?

Neither ZeroControl nor Sutro shows ads.

### Which is updated more often, ZeroControl or Sutro?

ZeroControl ships an update every 4 months, and Sutro every 2 months. Most recently, ZeroControl was updated on June 4, 2026 and Sutro on June 10, 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.*