# Sentnel vs HidroObserva

The clearest difference is iOS requirement: HidroObserva at 13.0 against Sentnel's 15.1. On price, update cadence, 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.

Sentnel ships an update every 3 weeks, HidroObserva fortnightly. The most recent releases landed on September 2, 2026 and September 12, 2026 respectively.

## The numbers

| Metric | Sentnel | HidroObserva |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Fortnightly** |
| Size | 63 MB | 64 MB |
| Requires iOS | 15.1 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [SENTNEL MONITORAMENTO LTDA](https://appshunter.io/developer/1574730680) | [Servicos e Informacoes do Brasil](https://appshunter.io/developer/1475781851) |

## What reviewers say

### Sentnel

[App page](https://appshunter.io/ios/app/sentnel/id1544355802)

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

**In-app purchases:** none


### HidroObserva

[App page](https://appshunter.io/ios/app/hidroobserva/id6449265378)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Sentnel free?

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

### Is HidroObserva free?

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

### Do Sentnel or HidroObserva have ads?

Neither Sentnel nor HidroObserva shows ads.

### Which is updated more often, Sentnel or HidroObserva?

Sentnel ships an update every 3 weeks, and HidroObserva fortnightly. Most recently, Sentnel was updated on September 2, 2026 and HidroObserva on September 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.*