# Wattson Pro vs Right Calculator

The clearest difference is in-app purchases: Right Calculator at none against Wattson Pro's 1. Wattson Pro's advantage is ads (none vs shown). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. Wattson Pro sells 1 one-off in-app purchase. Right Calculator asks for nothing beyond the download.

Wattson Pro ships an update every 4 days, Right Calculator every 6 days. The most recent releases landed on October 3, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Wattson Pro | Right Calculator |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | **Every 4 days** | Every 6 days |
| Size | 44 MB | 41 MB |
| Requires iOS | 15.1 | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [Marin Martinovic](https://appshunter.io/developer/1871459610) | [Megabyte Software Inc.](https://appshunter.io/developer/1143972928) |

## What reviewers say

### Wattson Pro

[App page](https://appshunter.io/ios/app/wattson-pro/id6760766587)

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Wattson Pro | $5.99 | one-time |


### Right Calculator

[App page](https://appshunter.io/ios/app/right-calculator/id6768528621)

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

**In-app purchases:** none


## Frequently asked questions

### Is Wattson Pro free?

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

### Is Right Calculator free?

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

### Do Wattson Pro or Right Calculator have ads?

Right Calculator shows ads; Wattson Pro does not.

### Which is updated more often, Wattson Pro or Right Calculator?

Wattson Pro ships an update every 4 days, and Right Calculator every 6 days. Most recently, Wattson Pro was updated on October 3, 2026 and Right Calculator 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.*