# HD Center vs RotaCalc

The clearest difference is in-app purchases: HD Center at none against RotaCalc's 1. HD Center also leads on iOS requirement (13.4 vs 15.1). RotaCalc's advantage is update cadence (every 3 days vs every 4 months). On price, ads and device support there is nothing between them.

Both are free to download. RotaCalc sells 1 in-app purchase, starting at $0.99 per month. HD Center asks for nothing beyond the download.

HD Center ships an update every 4 months, RotaCalc every 3 days. The most recent releases landed on November 4, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | HD Center | RotaCalc |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 3 days** |
| Size | 120 MB | 52 MB |
| Requires iOS | **13.4** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [HD CENTER - PROJETOS LOCACOES E SERVICOS LTDA](https://appshunter.io/developer/1627739577) | [TUNGALABS, UNIPESSOAL LDA](https://appshunter.io/developer/6788111035) |

## What reviewers say

### HD Center

[App page](https://appshunter.io/ios/app/hd-center/id6471662969)

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

**In-app purchases:** none


### RotaCalc

[App page](https://appshunter.io/ios/app/rotacalc/id6800042700)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Rotacalc app | $0.99 | per month |


## Frequently asked questions

### Is HD Center free?

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

### Is RotaCalc free?

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

### Do HD Center or RotaCalc have ads?

Neither HD Center nor RotaCalc shows ads.

### Which is updated more often, HD Center or RotaCalc?

HD Center ships an update every 4 months, and RotaCalc every 3 days. Most recently, HD Center was updated on November 4, 2026 and RotaCalc on October 29, 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.*