# ThinkDiag+ vs Advancer AD20

The clearest difference is review sentiment: ThinkDiag+ at 74% against Advancer AD20's 14%. ThinkDiag+ also leads on rating (4.5 vs 2.4) and ratings volume (4.3K vs 62). Advancer AD20's advantage is monetization model (free vs free with in-app purchases). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ThinkDiag+ holds the better App Store score, 4.5 against 2.4. That said, the two scores are not equally well evidenced: ThinkDiag+ has 4.3K ratings behind it against 62, so its average is the more settled of the two. Written reviews point the same way: 74% of ThinkDiag+'s written reviews are positive against 14% of Advancer AD20's.

ThinkDiag+ ships an update every 3 weeks, Advancer AD20 monthly. The most recent releases landed on October 16, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | ThinkDiag+ | Advancer AD20 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (4.3K ratings)](https://appshunter.io/ios/app/thinkdiag-plus/id1483420979/reviews)** | [2.4 (62 ratings)](https://appshunter.io/ios/app/advancer-ad20/id6444664990/reviews) |
| Number of ratings | **4.3K** | 62 |
| Positive reviews | **74.1% of reviews** | 13.9% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Monthly |
| Monetization | Free with in-app purchases | **Free** |
| Size | 539 MB | 496 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 12+ |
| Developer | [THINKCAR INC](https://appshunter.io/developer/1464847379) | [深圳市云伽未来智能技术有限公司](https://appshunter.io/developer/1638728786) |

## 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


### Advancer AD20

[App page](https://appshunter.io/ios/app/advancer-ad20/id6444664990)

This app connects to a smart OBD dongle to provide vehicle health checks, diagnosis, and real-time monitoring. It helps identify fault codes, analyze driving habits, and offers maintenance reminders for enhanced driving safety.

**Highlights:** OBD-II Diagnosis, In-depth system check, Live vehicle data monitoring, Maintenance light reset, Trip recorder, Driving habits analysis

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- 👍 Easy installation and pairing
- 👍 Straightforward iPad pairing
- 👍 Full diagnostic capabilities
- 👍 Satisfied with results
- 👍 Works as expected for some users

**What reviewers complain about**

- 🐛 Cannot connect to device
- 🐛 Scanner tied to another account
- 🐛 Required account creation
- 🐛 Invalid email for account creation
- 🐛 Does not connect to specific car models

**Reported bugs**

- Cannot connect to scanner
- Scanner tied to another account
- Account creation issues (invalid email)
- Device stops working after registration
- Login timeouts

**Requested features**

- Add more languages, including Chinese
- Improve information availability for various car models
- Fix issues with iOS updates
- Improve app layout and navigation
- Increase text size and contrast


## Frequently asked questions

### Is ThinkDiag+ free?

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

### Is Advancer AD20 free?

Advancer AD20 is free to download, with no in-app purchases.

### Which has better reviews, ThinkDiag+ or Advancer AD20?

ThinkDiag+ is rated higher. ThinkDiag+ averages 4.5 out of 5 from 4.3K ratings, while Advancer AD20 averages 2.4 from 62 ratings.

### Do ThinkDiag+ or Advancer AD20 have ads?

Neither ThinkDiag+ nor Advancer AD20 shows ads.

### Which is updated more often, ThinkDiag+ or Advancer AD20?

ThinkDiag+ ships an update every 3 weeks, and Advancer AD20 monthly. Most recently, ThinkDiag+ was updated on October 16, 2026 and Advancer AD20 on October 12, 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.*