# WTR Notebook vs Periodic Table

The clearest difference is update cadence: WTR Notebook at every 2 months against Periodic Table's every 28 months. WTR Notebook also leads on iOS requirement (11.0 vs 16.0). Periodic Table's advantage is price ($1.99 vs $4.99). On ads, in-app purchases and device support there is nothing between them.

WTR Notebook costs $4.99 and Periodic Table $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

WTR Notebook ships an update every 2 months, Periodic Table every 28 months. The most recent releases landed on September 28, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | WTR Notebook | Periodic Table |
| --- | --- | --- |
| Price | $4.99 | **$1.99** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 28 months |
| Size | 14 MB | 1 MB |
| Requires iOS | **11.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Digitalt Hjarta AB](https://appshunter.io/developer/886129484) | [Jorge Lucioni Charalla](https://appshunter.io/developer/1198674844) |

## What reviewers say

### WTR Notebook

[App page](https://appshunter.io/ios/app/wtr-notebook/id1019261013)

**Features:** macOS Compatibility

**In-app purchases:** none


### Periodic Table

[App page](https://appshunter.io/ios/app/periodic-table-elements/id1482354618)

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

**In-app purchases:** none


## Frequently asked questions

### Is WTR Notebook free?

WTR Notebook costs $4.99, with no in-app purchases.

### Is Periodic Table free?

Periodic Table costs $1.99, with no in-app purchases.

### Do WTR Notebook or Periodic Table have ads?

Neither WTR Notebook nor Periodic Table shows ads.

### Which is updated more often, WTR Notebook or Periodic Table?

WTR Notebook ships an update every 2 months, and Periodic Table every 28 months. Most recently, WTR Notebook was updated on September 28, 2026 and Periodic Table 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.*