# Mental Arithmetic Helper vs WatchNotes

The clearest difference is ads: WatchNotes at none against Mental Arithmetic Helper's shown. WatchNotes also leads on update cadence (daily vs fortnightly). Mental Arithmetic Helper's advantage is iOS requirement (15.8.3 vs 18.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Mental Arithmetic Helper ships an update fortnightly, WatchNotes daily. The most recent releases landed on October 11, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Mental Arithmetic Helper | WatchNotes |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Fortnightly | **Daily** |
| Size | 37 MB | 5 MB |
| Requires iOS | **15.8.3** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Hideaki Uchikoshi](https://appshunter.io/developer/1559575002) | [Ilia Evseev](https://appshunter.io/developer/6773412481) |

## What reviewers say

### Mental Arithmetic Helper

[App page](https://appshunter.io/ios/app/mental-arithmetic-helper/id6502036493)

**Features:** macOS Compatibility

**In-app purchases:** none


### WatchNotes

[App page](https://appshunter.io/ios/app/watchnotes-wrist-pdf-reader/id6780066873)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Mental Arithmetic Helper free?

Mental Arithmetic Helper is free to download, with no in-app purchases.

### Is WatchNotes free?

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

### Do Mental Arithmetic Helper or WatchNotes have ads?

Mental Arithmetic Helper shows ads; WatchNotes does not.

### Which is updated more often, Mental Arithmetic Helper or WatchNotes?

Mental Arithmetic Helper ships an update fortnightly, and WatchNotes daily. Most recently, Mental Arithmetic Helper was updated on October 11, 2026 and WatchNotes on October 6, 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.*