# Gt vs simos.app

Gt and simos.app are too close to call on the numbers: across 7 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

Gt ships an update weekly, simos.app every 4 days. The most recent releases landed on September 19, 2026 and September 12, 2026 respectively.

## The numbers

| Metric | Gt | simos.app |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/simosapp/id6760018423/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Weekly | **Every 4 days** |
| Monetization | Free | Free |
| Size | 55 MB | 6 MB |
| Requires iOS | **17.4** | 17.6 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Athanasios Farmakis](https://appshunter.io/developer/1711239231) | [Tycho Sebastian Holzer](https://appshunter.io/developer/1882338941) |

## What reviewers say

### Gt

[App page](https://appshunter.io/ios/app/gt-flasher/id6469004059)

This application enables users to log and configure modern engine and gearbox management systems. It utilizes the UDS protocol over OBD II with open-source OBD BLE devices. The app supports programming recovery for most platforms if a configuration procedure is interrupted.

**Highlights:** Log engine management systems, Configure gearbox management systems, UDS protocol support, OBD II connectivity, Open source OBD BLE device compatibility, Programming recovery feature

**In-app purchases:** none


### simos.app

[App page](https://appshunter.io/ios/app/simosapp/id6760018423)

This tool provides diagnostic, data logging, and flashing capabilities for VAG petrol engines with specific Simos ECUs. Monitor real-time engine parameters, analyze recorded sessions with graphs, and update your ECU with stock or custom tunes.

**Highlights:** Real-time ECU parameter monitoring, Live data logging via Bluetooth LE, ECU identification (software/calibration IDs), Multi-channel graph analysis of logged sessions, ECU and TCU flashing (stock and custom tunes), Support for Simos 18.x and 12.1 ECUs

**In-app purchases:** none


## Frequently asked questions

### Is Gt free?

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

### Is simos.app free?

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

### Do Gt or simos.app have ads?

Neither Gt nor simos.app shows ads.

### Which is updated more often, Gt or simos.app?

Gt ships an update weekly, and simos.app every 4 days. Most recently, Gt was updated on September 19, 2026 and simos.app on September 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.*