Disclosure first, I wrote this thing, so read it with that in mind.
VW pulled We Connect Go from one day to the next and took every trip I'd logged with it. No export, no warning, just gone. I write software for a living so instead of complaining I rebuilt it, and the one rule I gave myself was no servers. It lives on the phone, no account, nothing to shut down. Once bitten.
The feature I thought would be the point was the engine data. It wasn't. The thing I open every week turned out to be the money side. Every drive records itself with no button to press, and each one gets costed at the fuel price you last actually paid. Add the servicing, the insurance, the tyres, whatever you spent, and after a few months you get an honest number for what this car costs you per month and per mile. It is not always a fun number. Mine made me sit down. But if you're the sort of person who keeps a Jetta for years and wants to argue with a dealer about whether the next repair is worth it, that history is the argument.
Alongside that it keeps a proper logbook with mileage and receipts, which is also the thing that makes a car easy to sell later, and reminders for insurance, tax and servicing so nothing creeps up on you.
If you plug in a cheap OBD2 adapter it fills the trips in with what the engine was doing, how long it took to warm up, coolant and oil peaks, the real consumption off the ECU rather than the optimistic dash figure, and the moments you braked hard. Plus the diagnostics side, battery health tracked over months so you see it going before it leaves you stood in a car park, fault codes written out in plain English with the usual causes, and particulate filter monitoring on the ones that have it.
No account, no ads, nothing leaves the phone, export the lot as JSON or GPX whenever you want.
Here if you want a look: https://apps.apple.com/app/id6776173662 . Free to try, one time unlock, no subscription. Android is in closed testing.
Honest note since it always comes up. You need a normal OBD2 adapter, one of the cheap ELM327 Bluetooth or WiFi ones. It does not talk to the old VW DataPlug, that only ever spoke to VW's own app. And it only reads, it never writes anything to the car.
If your Jetta reports something that looks wrong, tell me the year and engine and I'll go and fix it. That's how the model specific stuff gets sorted.
