# ThinkDiag+ vs DFirstCoder

The clearest difference is in-app purchases: ThinkDiag+ at none against DFirstCoder's 8. ThinkDiag+ also leads on ratings volume (4.3K vs 5). DFirstCoder's advantage is rating (4.8 vs 4.5). On price, review sentiment, update cadence and ads there is nothing between them.

Both are free to download. DFirstCoder sells 8 in-app purchases, starting at $108.99 per year. ThinkDiag+ asks for nothing beyond the download.

DFirstCoder holds the better App Store score, 4.8 against 4.5. That said, the two scores are not equally well evidenced: ThinkDiag+ has 4.3K ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 74% of ThinkDiag+'s written reviews are positive against 67% of DFirstCoder's, so the app with the better star average is not the one people write more warmly about.

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on September 25, 2026 and September 6, 2026 respectively.

## The numbers

| Metric | ThinkDiag+ | DFirstCoder |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (4.3K ratings)](https://appshunter.io/ios/app/thinkdiag-plus/id1483420979/reviews) | **[4.8 (5 ratings)](https://appshunter.io/ios/app/dfirstcoder/id1637894055/reviews)** |
| Number of ratings | **4.3K** | 5 |
| Positive reviews | **73.6% of reviews** | 66.7% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 539 MB | 94 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 17+ | 17+ |
| Developer | [THINKCAR INC](https://appshunter.io/developer/1464847379) | [Shenzhen QiXin Technology Co., Ltd.](https://appshunter.io/developer/1637894777) |

## What reviewers say

### ThinkDiag+

[App page](https://appshunter.io/ios/app/thinkdiag-plus/id1483420979)

This app provides professional-level vehicle diagnostics, offering features like reading/clearing fault codes, data flow analysis, and special maintenance functions. It supports a wide range of car brands and allows users to subscribe to specific diagnostic software. Connects via Bluetooth to your smartphone for intelligent vehicle analysis.

**Highlights:** OE-level diagnostic functions, Full OBD II diagnosis, Special maintenance functions, Supports 100+ vehicle brands, Automatic VIN reading, Professional diagnostic reports, In-app user community

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 🚀 Easy to use
- 🚀 Powerful diagnostic capabilities
- 🚀 Affordable price
- 🚀 Helpful customer support
- 🚀 Versatile for DIY and professionals

**What reviewers complain about**

- 🐛 Occasional crashes or freezes
- 🐛 Compatibility issues with certain vehicles
- 🔒 Concerns about annual subscription fees
- 🔒 Limited functionality on iOS devices

**Reported bugs**

- Failure to recognize VIN or vehicle information
- Inability to clear certain error codes
- Inconsistent performance across different devices

**Requested features**

- Improved user interface and navigation
- More detailed troubleshooting guides
- Expanded vehicle coverage and special functions
- Offline mode for diagnostics


### DFirstCoder

[App page](https://appshunter.io/ios/app/dfirstcoder/id1637894055)

This app provides comprehensive vehicle diagnostics and customization for car owners. It offers one-click app features for easy operation, Bluetooth connectivity, and the ability to read/clear trouble codes, perform smog checks, and view live data. It supports a wide range of vehicle models.

**Highlights:** One-click apps for easy operation, Comprehensive diagnostic features, Bluetooth wireless connectivity, Read and clear trouble codes, Smog check functionality, Live data display, Supports VAG, BMW, Mercedes-Benz models

**Features:** Family Sharing

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Plan Subscription | $108.99 | per year |
| Pro Plan Subscription (Family) | $158.99 | per year |
| 350 QD | $4.99 | one-time |
| 700 QD | $9.95 | one-time |
| 1400 QD | $19.49 | one-time |
| 3500 QD | $49.99 | one-time |
| 7000 QD | $96.99 | one-time |
| 10500 QD | $145.99 | one-time |


## Frequently asked questions

### Is ThinkDiag+ free?

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

### Is DFirstCoder free?

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

### Which has better reviews, ThinkDiag+ or DFirstCoder?

DFirstCoder is rated higher. ThinkDiag+ averages 4.5 out of 5 from 4.3K ratings, while DFirstCoder averages 4.8 from 5 ratings.

### Do ThinkDiag+ or DFirstCoder have ads?

Neither ThinkDiag+ nor DFirstCoder shows ads.

### Which is updated more often, ThinkDiag+ or DFirstCoder?

ThinkDiag+ ships an update every 3 weeks, and DFirstCoder every 3 weeks. Most recently, ThinkDiag+ was updated on September 25, 2026 and DFirstCoder on September 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.*