# HydroCalc Basic vs GRAAS

The clearest difference is in-app purchases: GRAAS at none against HydroCalc Basic's 1. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. HydroCalc Basic sells 1 one-off in-app purchase. GRAAS asks for nothing beyond the download.

HydroCalc Basic ships an update every 11 days, GRAAS every 3 weeks. The most recent releases landed on October 4, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | HydroCalc Basic | GRAAS |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 11 days** | Every 3 weeks |
| Size | 35 MB | 30 MB |
| Requires iOS | 15.1 | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Transparent Blue Water LLC](https://appshunter.io/developer/1847968351) | [vilius Marcinkus](https://appshunter.io/developer/1877407095) |

## What reviewers say

### HydroCalc Basic

[App page](https://appshunter.io/ios/app/hydrocalc-basic/id6752577110)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium - Flow Units & Ad-Free | $1.99 | one-time |


### GRAAS

[App page](https://appshunter.io/ios/app/graas/id6759206550)

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

**In-app purchases:** none


## Frequently asked questions

### Is HydroCalc Basic free?

HydroCalc Basic is free to download, with in-app purchases available.

### Is GRAAS free?

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

### Do HydroCalc Basic or GRAAS have ads?

Neither HydroCalc Basic nor GRAAS shows ads.

### Which is updated more often, HydroCalc Basic or GRAAS?

HydroCalc Basic ships an update every 11 days, and GRAAS every 3 weeks. Most recently, HydroCalc Basic was updated on October 4, 2026 and GRAAS on October 7, 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.*