# Bluebits vs HydroCalc Basic

The clearest difference is in-app purchases: Bluebits at none against HydroCalc Basic's 1. Bluebits also leads on iOS requirement (11.0 vs 15.1). HydroCalc Basic's advantage is update cadence (every 11 days vs every 16 months). On price, ads and device support there is nothing between them.

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

Bluebits ships an update every 16 months, HydroCalc Basic every 11 days. The most recent releases landed on September 9, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | Bluebits | HydroCalc Basic |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 16 months | **Every 11 days** |
| Size | 47 MB | 35 MB |
| Requires iOS | **11.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Talgil](https://appshunter.io/developer/1139561018) | [Transparent Blue Water LLC](https://appshunter.io/developer/1847968351) |

## What reviewers say

### Bluebits

[App page](https://appshunter.io/ios/app/bluebits/id1181359007)

**Features:** macOS Compatibility

**In-app purchases:** none


### 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 |


## Frequently asked questions

### Is Bluebits free?

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

### Is HydroCalc Basic free?

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

### Do Bluebits or HydroCalc Basic have ads?

Neither Bluebits nor HydroCalc Basic shows ads.

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

Bluebits ships an update every 16 months, and HydroCalc Basic every 11 days. Most recently, Bluebits was updated on September 9, 2026 and HydroCalc Basic on September 8, 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.*