# Waa Waa vs PDFkai

The clearest difference is in-app purchases: PDFkai at none against Waa Waa's 1. Waa Waa's advantage is iOS requirement (13.0 vs 18.5). On price, update cadence, ads and device support there is nothing between them.

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

Both ship on a similar rhythm, roughly every 2 days. The most recent releases landed on October 15, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | Waa Waa | PDFkai |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 days | Every 2 days |
| Size | 59 MB | 1 MB |
| Requires iOS | **13.0** | 18.5 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [1tier](https://appshunter.io/developer/1758267913) | [Kohei YAMAMOTO](https://appshunter.io/developer/1886637159) |

## What reviewers say

### Waa Waa

[App page](https://appshunter.io/ios/app/waa-waa/id6752776912)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Plan (No Ads) | $0.99 | per month |


### PDFkai

[App page](https://appshunter.io/ios/app/pdfkai/id6760888905)

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

**In-app purchases:** none


## Frequently asked questions

### Is Waa Waa free?

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

### Is PDFkai free?

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

### Do Waa Waa or PDFkai have ads?

Neither Waa Waa nor PDFkai shows ads.

### Which is updated more often, Waa Waa or PDFkai?

Waa Waa ships an update every 2 days, and PDFkai every 2 days. Most recently, Waa Waa was updated on October 15, 2026 and PDFkai on October 14, 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.*