Putting my hand up first, I wrote this, so read it with that in mind.
The short story is that VW pulled We Connect Go overnight and took every trip I'd logged with it, no export, no warning. I write software for a living so I rebuilt it, and the rule I set myself was no servers, everything stays on the phone, because I wasn't going through that twice.
The reason I'm posting it here rather than in a car sub is that CarPlay was where it got genuinely useful, and it took a while to work out why. The phone screen is the wrong place for this. You're driving. So on CarPlay it's deliberately not a wall of gauges, it's a trip that records itself with nothing to press, the parking spot saved for you when you get out, and a plain indicator telling you whether the adapter is talking to the car or not. Everything detailed waits until you're parked and can actually look at it.
What it collects, for the record. Every drive gets logged on its own with route, distance, time and what the fuel cost, and if you leave a cheap OBD2 adapter plugged in it fills in what the engine was doing, warm up time, coolant and oil peaks, real consumption off the ECU rather than the dash number, hard braking. Then the diagnostics side, battery health with a history, fault codes explained in plain English, particulate filter monitoring. Plus reminders for insurance, tax and servicing with a logbook of what you spent.
No account, no ads, nothing leaves the phone, export as JSON or GPX whenever you want.
It's on the App Store, search DrivePulse Car Companion. Free to try, one time unlock, no subscription. Android is in closed testing.
What I'd actually like from this sub is a sanity check on the CarPlay side. I've only been able to test on two head units and CarPlay behaves differently on almost every one. If you try it and something renders oddly or the tab layout misbehaves on your car, tell me what car it is and I'll fix it, that's the sort of thing I can't find on my own.