# simos.app vs ECU Map Switcher by D

simos.app and ECU Map Switcher by D are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support 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.

## The numbers

| Metric | simos.app | ECU Map Switcher by D |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/simosapp/id6760018423/reviews)** | — |
| Number of ratings | **2** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 days | — |
| Monetization | Free | — |
| Size | 6 MB | 1 MB |
| Requires iOS | 17.6 | **17.0** |
| Devices | iPhone | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Tycho Sebastian Holzer](https://appshunter.io/developer/1882338941) | [LUN LIU](https://appshunter.io/developer/1890125123) |

## What reviewers say

### 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


### ECU Map Switcher by D

[App page](https://appshunter.io/ios/app/ecu-map-switcher-by-d-sync/id6761521552)

**In-app purchases:** none


## Frequently asked questions

### Is simos.app free?

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

### Is ECU Map Switcher by D free?

ECU Map Switcher by D is free to download, with no in-app purchases.

### Do simos.app or ECU Map Switcher by D have ads?

Neither simos.app nor ECU Map Switcher by D shows ads.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*