# HydroTimer vs PDF Reader

The clearest difference is in-app purchases: HydroTimer at none against PDF Reader's 3. PDF Reader's advantage is update cadence (monthly vs every 10 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. PDF Reader sells 3 in-app purchases, starting at $4.99 per 7 days. HydroTimer asks for nothing beyond the download.

HydroTimer ships an update every 10 months, PDF Reader monthly. The most recent releases landed on October 22, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | HydroTimer | PDF Reader |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/pdf-reader-viewer-and-editor/id6756208851/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 10 months | **Monthly** |
| Monetization | — | Free with in-app purchases |
| Size | 2 MB | 111 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Aurelis Limited](https://appshunter.io/developer/1821243565) | [明菲 张](https://appshunter.io/developer/1749421507) |

## What reviewers say

### HydroTimer

[App page](https://appshunter.io/ios/app/hydrotimer/id6748376181)

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

**In-app purchases:** none


### PDF Reader

[App page](https://appshunter.io/ios/app/pdf-reader-viewer-and-editor/id6756208851)

Easily open, view, and manage PDF files on your iPhone or iPod. This lightweight tool offers a clean interface for a distraction-free reading experience of work documents, study materials, or personal files.

**Highlights:** Open PDF documents, View PDF files, Manage PDF files, Clean interface, Distraction-free reading

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Subscription | $4.99 | per 7 days |
| Monthly Subscription | $9.99 | per month |
| Annual Subscription | $99.99 | per year |


## Frequently asked questions

### Is HydroTimer free?

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

### Is PDF Reader free?

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

### Do HydroTimer or PDF Reader have ads?

Neither HydroTimer nor PDF Reader shows ads.

### Which is updated more often, HydroTimer or PDF Reader?

HydroTimer ships an update every 10 months, and PDF Reader monthly. Most recently, HydroTimer was updated on October 22, 2026 and PDF Reader on October 10, 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.*