# e vs AQS

e and AQS 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.

e ships an update every 2 months, AQS every 5 weeks. The most recent releases landed on September 19, 2026 and September 14, 2026 respectively.

## The numbers

| Metric | e | AQS |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/e-sens/id1585074022/reviews)** | — |
| Number of ratings | **3** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 5 weeks** |
| Monetization | Ad-supported | — |
| Size | 32 MB | 70 MB |
| Requires iOS | **15.6** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [e-sens, Inc.](https://appshunter.io/developer/1479061797) | [Aquarius-Spectrum](https://appshunter.io/developer/1613033707) |

## What reviewers say

### e

[App page](https://appshunter.io/ios/app/e-sens/id1585074022)

This tool allows water quality professionals to collect, manage, analyze, and track water quality test parameters. It is designed for water treatment facilities and professionals in the field.

**Highlights:** Water quality data collection, Data management, Analysis of test parameters, Tracking of water quality, Designed for professionals, Supports water treatment facilities

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

**In-app purchases:** none


### AQS

[App page](https://appshunter.io/ios/app/aqs-sys-app/id1613033435)

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

**In-app purchases:** none


## Frequently asked questions

### Is e free?

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

### Is AQS free?

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

### Do e or AQS have ads?

Neither e nor AQS shows ads.

### Which is updated more often, e or AQS?

e ships an update every 2 months, and AQS every 5 weeks. Most recently, e was updated on September 19, 2026 and AQS on September 14, 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.*