# PDF Merger vs Simple Letter

The clearest difference is update cadence: Simple Letter at every 2 weeks against PDF Merger's every 9 months. PDF Merger's advantage is iOS requirement (17.0 vs 26.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. PDF Merger sells 3 in-app purchases, starting at $1.99 per 7 days and Simple Letter sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

PDF Merger ships an update every 9 months, Simple Letter every 2 weeks. The most recent releases landed on October 7, 2026 and October 23, 2026 respectively.

## The numbers

| Metric | PDF Merger | Simple Letter |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 9 months | **Every 2 weeks** |
| Size | 2 MB | 5 MB |
| Requires iOS | **17.0** | 26.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 9+ |
| Developer | [Ahmet Bostancklioglu](https://appshunter.io/developer/1780554362) | [Wolfram Wacker](https://appshunter.io/developer/1843968515) |

## What reviewers say

### PDF Merger

[App page](https://appshunter.io/ios/app/pdf-merger-combine-and-split/id6738798786)

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro — Weekly | $1.99 | per 7 days |
| Pro — Yearly | $29.99 | per year |
| PDF Merger Lifetime | $59.99 | one-time |


### Simple Letter

[App page](https://appshunter.io/ios/app/simple-letter/id6753818401)

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Simple Letter Pro | $1.99 | one-time |
| Small Coffee (voluntary tip) | $1.99 | one-time |
| Large Coffee (voluntary tip) | $5.99 | one-time |


## Frequently asked questions

### Is PDF Merger free?

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

### Is Simple Letter free?

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

### Do PDF Merger or Simple Letter have ads?

Neither PDF Merger nor Simple Letter shows ads.

### Which is updated more often, PDF Merger or Simple Letter?

PDF Merger ships an update every 9 months, and Simple Letter every 2 weeks. Most recently, PDF Merger was updated on October 7, 2026 and Simple Letter on October 23, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*