# SPRINGviewer vs Hydro

The clearest difference is update cadence: SPRINGviewer at weekly against Hydro's monthly. On price, ads, 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.

SPRINGviewer ships an update weekly, Hydro monthly. The most recent releases landed on September 12, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | SPRINGviewer | Hydro |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Weekly** | Monthly |
| Size | 73 MB | 7 MB |
| Requires iOS | 26.0 | 26.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Torsten Seidel](https://appshunter.io/developer/1609083675) | [Patrick](https://appshunter.io/developer/385768716) |

## What reviewers say

### SPRINGviewer

[App page](https://appshunter.io/ios/app/springviewer/id1609123265)

**Features:** macOS Compatibility

**In-app purchases:** none


### Hydro

[App page](https://appshunter.io/ios/app/hydro-aquatic-data-hub/id6477622181)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is SPRINGviewer free?

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

### Is Hydro free?

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

### Do SPRINGviewer or Hydro have ads?

Neither SPRINGviewer nor Hydro shows ads.

### Which is updated more often, SPRINGviewer or Hydro?

SPRINGviewer ships an update weekly, and Hydro monthly. Most recently, SPRINGviewer was updated on September 12, 2026 and Hydro on September 22, 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.*