Straight answers.

It sends the same diagnostic commands a workshop tool uses and makes no permanent changes. Use it only on a vehicle you own, off public roads, for show and demonstration purposes.

No. The app is for a vehicle that is parked and stationary, off public roads. Operating non-standard lighting on a public road is illegal in most places, and it is unsafe for you and everyone around you.

No, that is unlikely. The app sends ordinary diagnostic commands to the lighting modules, and nothing it does is lasting.

Most adapters draw a small current even with the ignition off. Unplugging it when you are done is the safe habit, especially if the car will sit for days. The app itself sends nothing while it is not connected.

We recommend MBito OBD, vLinker BLE and KONNWEI Bluetooth LE adapters; they are the ones we test. Other ELM327-compatible Bluetooth LE adapters may work, but very cheap clones can be too slow for the fastest strobe patterns. If "strobe" or "max" looks choppy, drop to "fast" or "normal". MBito is a trademark of UAB Mbito. MercLight is independently developed and is not affiliated with, sponsored by, or endorsed by MBito.

1. Switch the ignition on. The engine does not need to run, but the lighting modules only answer when the car is awake. 2. Plug the adapter into the OBD-II port. 3. Open MercLight, tap Connect, and pick your adapter. The app reads the VIN, decodes the model, and unlocks the front ECU automatically.

Nothing happens. The lamps return to normal on their own, and you just reconnect and play again.

Cars from 2016 onward across the A, C, E and S-Class, CLA, CLS, GLC, GLE, GLS and G-Class ranges. What matters is the lighting module fitted, so the app identifies yours and shows only the effects it can run, before you buy.

The app identifies your lighting modules directly rather than guessing from the model name. If it doesn't recognise them, it asks our server for a newer mapping and downloads it on the spot. Some effects are free, so you can find out on your own car before buying.

Yes, on any supported car you own. The app identifies each car and shows what it can run before you buy anything.

An effect is a single animation: a police burst, a KITT scanner. A combo is a sequence of effects you build on the Effects screen; they play back-to-back, optionally looping. Gapless mode keeps the ECU unlocked across the whole combo so there's no pause between steps.

Both, launching together.

English, German, Spanish, French and Arabic, following your phone’s language setting. You can also choose one in Settings.

It's free to install, and some effects are free to try on your own car. Everything else is available in the app, sold through Apple or Google in your local currency.

No. Use Restore Purchases in the app. Purchases live with your Apple or Google account, so a new phone gets them back.

A device identifier and your car's VIN, sent to our own server to attach a purchase to your vehicle. Purchases, and which purchase screen you saw, are processed by RevenueCat on our behalf. No advertising, no tracking, and no sign-up: no email or password, only a random account ID our server issues. You can delete everything linked to you from inside the app. Full details in the privacy policy.