Log, flash & tune from your phone
Connect your phone to VW, Audi, Seat, Skoda and Cupra control units over OBD-II.
Live data logging is free — unlock flashing, tunes, coding and adaptations when you need them.
Simos 18 · Simos 12 · DQ250 · DQ381 (beta)
Live data logging is free — unlock flashing, tunes, coding and adaptations when you need them.
Simos 18 · Simos 12 · DQ250 · DQ381 (beta)
up to50Hz
high-speed logging
<1min
for a CAL flash
4
ECU and DSG families
Up and running in three steps
- 1
- 2
Plug in the dongle
Connect the simos.app OBD-II dongle (€55) or a compatible alternative. No laptop, no bench setup.Get the dongle → - 3
Log, then unlock what you need
Logging is free. Unlock flashing, tools, adaptations and coding for your car's VIN when you are ready.
Everything your car needs, in one app
From a first log to a full flash — without a laptop in the car.
Free
Live data logging
Watch boost, knock, lambda, timing and more live. Log at up to 10 Hz, or up to 50 Hz with high-speed logging where supported, and share runs through the cloud log viewer.
Flashing & tunes
Unlock, CAL flash and full flash supported Simos 18 ECUs over OBD-II. Use the Stage 1 wizard for a ready-made tune, or flash your own file from the Tune Editor.
DSG transmissions
Log and flash DQ250 MQB transmissions. DQ381 logging and flashing are live in beta.
Tools, adaptations & coding
Run wastegate adaption, long coding and guided wizards for pops & bangs or ethanol content. Some wizards, like Stage 1, are paid — others are free.
See it in the app
Hover to pause, or pick a feature.
Will it work on my car?
simos.app supports VW, Audi, Seat, Skoda and Cupra with these control units. The exact software version decides what is available.
Supported
Simos 18.1 / 18.6 / 18.10
Logging, unlock, CAL and full flashing.
Supported
Simos 12.1 / 12.2
Logging and factory updates. No unlock or custom files.
Supported
DQ250 MQB
Logging and flashing for all DQ250 MQB variants.
Beta
DQ381
Logging and flashing in beta. Only flash with the tools to recover the TCU.
Coming soon
MED17.5 / 17.5.1 / 17.5.2 / 17.5.5
Support is coming soon.
Not planned
Simos 19.x
Golf 8 R / Evo4 and other ECU families are not planned yet.
Known to work: Golf 7 GTI and R, Audi S3 8V and TTS, Leon Cupra, Octavia RS, Arteon and more.
See the full compatibility list →
See the full compatibility list →
For tuners: the Tune Editor
Dongle, app and editor work as one system. Read and flash from the phone, tune in the browser, and keep every file in your cloud library.
Edit in the browser
Open BIN, S19 and HEX files with structured definitions for Simos and DSG control units.
Patches built in
Add map switching, rolling anti-lag, launch control or flex fuel from the patch manager.
Logs on the map
Replay a log and see the active cells highlighted while you change the calibration.
Plans from €25 / month + tax
Built by people who tune
Made in Switzerland
Developed and supported by Holzer Consulting in Basel.
Open ecosystem
The simos.app dongle also works with SimosTools for Android and VW_Flash.
Learn before you flash
Step-by-step guides cover unlocking, flash types and flashing safety.
Read the guides →Common questions
Yes, for live data logging. Flashing, tools, adaptations and coding are unlocked for your car's VIN. Some wizards, like Stage 1, are paid; others are free.
VW, Audi, Seat, Skoda and Cupra with Simos 18 or Simos 12 ECUs, plus DQ250 MQB and DQ381 (beta) transmissions. Check your car.
Yes, you need an OBD-II interface. The simos.app dongle is built for the app and costs €55; compatible alternatives also work.
Yes, simos.app for Android is available as a direct download. The simos.app dongle also works with SimosTools for Android.
The app checks compatibility and corrects checksums before writing. Read the flashing information before your first flash.
A browser-based calibration editor for tuners, with definitions, patches and log overlays. Files flow straight to the app for flashing.
Start with a free log
Download simos.app, plug in the dongle and see what your car is doing — in minutes.