# e85Cal vs simos.app

The clearest difference is update cadence: simos.app at every 4 days against e85Cal's every 4 months. simos.app also leads on rating (5.0 vs 4.7). e85Cal's advantage is ratings volume (35 vs 2) and iOS requirement (12.1 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 4.7. That said, the two scores are not equally well evidenced: e85Cal has 35 ratings behind it against 2, so its average is the more settled of the two.

e85Cal ships an update every 4 months, simos.app every 4 days. The most recent releases landed on September 26, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | e85Cal | simos.app |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (35 ratings)](https://appshunter.io/ios/app/e85cal/id1470313135/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/simosapp/id6760018423/reviews)** |
| Number of ratings | **35** | 2 |
| Positive reviews | 83.3% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 4 days** |
| Monetization | Free | Free |
| Size | 15 MB | 6 MB |
| Requires iOS | **12.1** | 17.6 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Michael Joe](https://appshunter.io/developer/1132486512) | [Tycho Sebastian Holzer](https://appshunter.io/developer/1882338941) |

## What reviewers say

### e85Cal

[App page](https://appshunter.io/ios/app/e85cal/id1470313135)

This app assists users in calculating the precise amounts of standard and ethanol gasoline needed to achieve a desired ethanol percentage in their fuel mix. It simplifies the process by taking into account tank size, current fuel level, and the ethanol content of available fuel types.

**Highlights:** Calculate ethanol percentage goal, Enter gas tank size, Input standard pump gas ethanol %, Input ethanol pump gas ethanol %, Set target ethanol % mix, Enter current fuel level %

**Features:** macOS Compatibility

**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 e85Cal free?

e85Cal 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, e85Cal or simos.app?

simos.app is rated higher. e85Cal averages 4.7 out of 5 from 35 ratings, while simos.app averages 5.0 from 2 ratings.

### Do e85Cal or simos.app have ads?

Neither e85Cal nor simos.app shows ads.

### Which is updated more often, e85Cal or simos.app?

e85Cal ships an update every 4 months, and simos.app every 4 days. Most recently, e85Cal was updated on September 26, 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.*