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 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
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 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
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

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.

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. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

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

ScorecardNo meaningful differences
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 frequencyWeeklyEvery 4 days — better
AdsNoNo
In-app purchasesNoNo
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

None

simos.app

No in-app purchases

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.

Other comparisons