Comparison

Gt vs simos.app

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Gt

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 if configuration procedures are interrupted.

Highlights
  • Log engine and gearbox management systems
  • Configure engine and gearbox management systems
  • Supports UDS protocol over OBD II
  • Utilizes open-source OBD BLE devices
  • Programming recovery for interrupted procedures
  • Restart failed configuration attempts
Read full description

Application that allows users log and configure modern Engine and Gearbox management systems using the UDS protocol over OBD II using various open source OBD BLE devices. Our application supports programming recovery on most supported platforms if the configuration procedure is interrupted. You can restart the procedure if the previous attempt has failed.

About

simos.app

This tool provides diagnostic, data logging, and flashing capabilities for specific VAG petrol engine ECUs. It allows real-time monitoring of engine parameters, ECU identification, and analysis of recorded sessions through multi-channel graphs. Users can also update their ECU with stock or custom tunes.

Highlights
  • Real-time ECU parameter logging
  • ECU identification
  • Multi-channel graph analysis
  • ECU and TCU flashing
  • Bluetooth LE connection
  • Support for Simos 18.x and 12.1 ECUs
Read full description

simos.app is a diagnostic, data logging and flashing tool built specifically for VAG petrol engines running Simos 18.1, 18.2, 18.6, 18.10 and Simos 12.1 ECUs. The platforms found in most modern TSI and TFSI engines across Audi, VW, Škoda, SEAT, Cupra and Porsche. LIVE DATA LOGGING Read ECU parameters directly in real time. Monitor boost pressure, injection timing, lambda, temperatures, torque and more at high sample rates over a Bluetooth LE connection. ECU IDENTIFICATION Read software versions, calibration IDs and hardware info straight from the control unit. LOG ANALYSIS Visualize recorded sessions with multi-channel graphs. Spot correlations between parameters without leaving the app. FLASHING Update your ECU and TCU to the latest version for your vehicle or flash a custom tune. Full features available for Simos 18.1/18.10 and 18.6. Flashing stock files or pre-unlocked ecus for Simos 18.2, 18.4, 18.41 and Simos 12.1. –– Built for enthusiasts, tuners and workshops who need more than a generic scan tool. Basic knowledge of ECU diagnostics is recommended. This app is for informational and diagnostic purposes only. Any modifications to vehicle systems are the sole responsibility of the user and must comply with local laws and regulations. –– Bluetooth LE OBD adapter required. Get yours here: https://simos.app/dongle Other compatible adapters: Macchina A0, DIY A0 clone https://github.com/Switchleg1/AMAleg require custom firmware: https://simos.app/dongle/firmware

Screenshots

Gt4 screens
simos.app4 screens

Verdict

The call

The clearest difference is in-app purchases: Gt at none against simos.app's 3. On price, update cadence, ads and monetization model there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. simos.app sells 3 one-off in-app purchases. Gt asks for nothing beyond the download.

UpkeepUpdate frequency

Gt ships an update every 2 weeks, simos.app weekly. The most recent releases landed on October 30, 2026 and October 31, 2026 respectively.

Scorecard1 real difference · 9 level
Gt versus simos.app: the parameters behind the verdict, then further details
ParameterGtsimos.app
PriceFreeFree
Rating—5.0 (2 ratings) — better
Positive reviews100.0% of reviews—
Number of ratings—2 — better
Update frequencyEvery 2 weeksWeekly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFreeFree
DevicesiPhone, iPad — betteriPhone
Requires iOS17.4 — better17.6
Further details — not scored
Size55 MB6 MB
Age rating4+4+
DeveloperAthanasios FarmakisTycho Sebastian Holzer

Customer experience

Gt

Written reviews3 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

simos.app

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Gt

No in-app purchases

3 purchases

simos.app

One-time3
  • App VIN Unlock$17.99
  • Wizard: Pops & Bangs - Single Bin$17.99
  • Stage 1 Bin$179.99

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 in-app purchases available.
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 every 2 weeks, and simos.app weekly. Most recently, Gt was updated on October 30, 2026 and simos.app on October 31, 2026.

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