# ZDOBD vs PDF Reader

The clearest difference is rating: PDF Reader at 4.7 against ZDOBD's 2.0. PDF Reader also leads on review sentiment (37% vs 0%) and ratings volume (665 vs 4). ZDOBD's advantage is in-app purchases (none vs 11) and ads (none vs shown). On price, monetization model and device support there is nothing between them.

Both are free to download. PDF Reader sells 9 in-app purchases, starting at $3.99 per 7 days. ZDOBD asks for nothing beyond the download.

PDF Reader holds the better App Store score, 4.7 against 2.0. That said, the two scores are not equally well evidenced: PDF Reader has 665 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 0% of ZDOBD's written reviews are positive against 37% of PDF Reader's.

ZDOBD ships an update monthly, PDF Reader every 8 days. The most recent releases landed on September 8, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | ZDOBD | PDF Reader |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.0 (4 ratings)](https://appshunter.io/ios/app/zdobd/id6449920963/reviews) | **[4.7 (665 ratings)](https://appshunter.io/ios/app/pdf-reader-editor-and-scanner/id6739480825/reviews)** |
| Number of ratings | 4 | **665** |
| Positive reviews | 0.0% of reviews | **37.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Monthly | **Every 8 days** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 22 MB | 118 MB |
| Requires iOS | **15.6** | 17.6 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [深圳市正德友邦科技有限公司](https://appshunter.io/developer/1691030696) | [DAOWEI NETWORK TECHNOLOGY PTE.LTD.](https://appshunter.io/developer/1547755677) |

## What reviewers say

### ZDOBD

[App page](https://appshunter.io/ios/app/zdobd/id6449920963)

This diagnostic tool connects to portable diesel vehicle devices via Bluetooth to perform comprehensive vehicle checks. It allows users to view ECU information, diagnose and clear faults, monitor real-time data, and conduct specific tests like DPF regeneration.

**Highlights:** Bluetooth connectivity, ECU version information, Vehicle fault diagnosis and clearing, Real-time data flow monitoring, DPF regeneration, SCR testing

**Features:** macOS Compatibility

**In-app purchases:** none


### PDF Reader

[App page](https://appshunter.io/ios/app/pdf-reader-editor-and-scanner/id6739480825)

This app provides comprehensive PDF management, including reading, editing, and scanning. It uses AI for intelligent document recognition, summarization, and conversion to various formats. Securely store and access your files in the cloud or from popular services.

**Highlights:** AI-powered PDF editing and summarization, Intelligent document scanning with OCR, Convert between PDF and other file formats, Annotate, sign, and fill PDF forms, Cloud storage integration (Google Drive, OneDrive), Merge, split, lock, and compress PDFs

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

**In-app purchases (9)**

| Purchase | Price | Billing |
| --- | --- | --- |
| One Week | $3.99 | per 7 days |
| One Week | $3.99 | per 7 days |
| One Week | $7.99 | per 7 days |
| One Week | $7.99 | per 7 days |
| One Month | $12.99 | per month |
| One Year | $49.99 | per year |
| One Year | $76.99 | per year |
| One Year | $76.99 | per year |
| Lifetime | $99.99 | one-time |


## Frequently asked questions

### Is ZDOBD free?

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

### Is PDF Reader free?

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

### Which has better reviews, ZDOBD or PDF Reader?

PDF Reader is rated higher. ZDOBD averages 2.0 out of 5 from 4 ratings, while PDF Reader averages 4.7 from 665 ratings.

### Do ZDOBD or PDF Reader have ads?

PDF Reader shows ads; ZDOBD does not.

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

ZDOBD ships an update monthly, and PDF Reader every 8 days. Most recently, ZDOBD was updated on September 8, 2026 and PDF Reader on September 23, 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.*