# NotosAR vs HydroTech Pocket Engineer

The clearest difference is iOS requirement: NotosAR at 13.0 against HydroTech Pocket Engineer's 15.0. 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.

Both ship on a similar rhythm, roughly monthly. The most recent releases landed on October 2, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | NotosAR | HydroTech Pocket Engineer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | Monthly |
| Size | 423 MB | 3 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [NETZSCH DO BRASIL INDUSTRIA E COMERCIO LTDA](https://appshunter.io/developer/1755476547) | [michael schricker](https://appshunter.io/developer/1895753612) |

## What reviewers say

### NotosAR

[App page](https://appshunter.io/ios/app/notosar/id6511209787)

**In-app purchases:** none


### HydroTech Pocket Engineer

[App page](https://appshunter.io/ios/app/hydrotech-pocket-engineer/id6764373443)

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

**In-app purchases:** none


## Frequently asked questions

### Is NotosAR free?

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

### Is HydroTech Pocket Engineer free?

HydroTech Pocket Engineer is free to download, with no in-app purchases.

### Do NotosAR or HydroTech Pocket Engineer have ads?

Neither NotosAR nor HydroTech Pocket Engineer shows ads.

### Which is updated more often, NotosAR or HydroTech Pocket Engineer?

NotosAR ships an update monthly, and HydroTech Pocket Engineer monthly. Most recently, NotosAR was updated on October 2, 2026 and HydroTech Pocket Engineer on October 1, 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.*