# Fuel vs simos.app

The clearest difference is rating: simos.app at 5.0 against Fuel's 3.1. simos.app also leads on update cadence (every 4 days vs every 10 months). Fuel's advantage is ratings volume (33 vs 2) and iOS requirement (13.4 vs 17.6). On price, ads, in-app purchases and monetization model there is nothing between them.

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

simos.app holds the better App Store score, 5.0 against 3.1. That said, the two scores are not equally well evidenced: Fuel has 33 ratings behind it against 2, so its average is the more settled of the two.

Fuel ships an update every 10 months, simos.app every 4 days. The most recent releases landed on October 6, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | Fuel | simos.app |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.1 (33 ratings)](https://appshunter.io/ios/app/fuel-it-eca/id1004246767/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/simosapp/id6760018423/reviews)** |
| Number of ratings | **33** | 2 |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 10 months | **Every 4 days** |
| Monetization | Free | Free |
| Size | 20 MB | 6 MB |
| Requires iOS | **13.4** | 17.6 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Dmac Mobile Developments, LLC](https://appshunter.io/developer/372235786) | [Tycho Sebastian Holzer](https://appshunter.io/developer/1882338941) |

## What reviewers say

### Fuel

[App page](https://appshunter.io/ios/app/fuel-it-eca/id1004246767)

Monitor your vehicle's ethanol concentration and fuel temperature in real-time. This app wirelessly connects to a compatible Bluetooth module, freeing up your device's port for simultaneous charging and monitoring. It includes an ethanol fill-up concentration calculator and customizable display views.

**Highlights:** Real-time ethanol concentration monitoring, Real-time fuel temperature monitoring, Wireless Bluetooth connectivity, Ethanol fill-up concentration calculator, Fahrenheit or Celsius display options, Two display views

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

**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 Fuel free?

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

### Is simos.app free?

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

### Which has better reviews, Fuel or simos.app?

simos.app is rated higher. Fuel averages 3.1 out of 5 from 33 ratings, while simos.app averages 5.0 from 2 ratings.

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

Neither Fuel nor simos.app shows ads.

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

Fuel ships an update every 10 months, and simos.app every 4 days. Most recently, Fuel was updated on October 6, 2026 and simos.app on October 1, 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.*