Would an app that reviews your practice drives and tells you what a driving examiner would fault actually be useful, or am I overthinking it?

I've been mulling over an idea and wanted to get a reality check from people actually going through their driving test before I waste months on it. The concept: an app you mount in the car during private practice (with a parent/supervisor) that uses your phone's sensors and camera to analyse how you actually drove — things like harsh braking, speed, cornering, and how you approach junctions — then gives you a breakdown afterwards of what you did well and what needs work, roughly along the lines of what an examiner looks for. The thinking is that most people practising outside of paid lessons have no real feedback loop; you drive around for an hour with no idea whether you're improving or just cementing bad habits, and then you're paying £35+ an hour for an instructor to point out the same stuff. A longer-term feature I'm weighing up is using the front camera on guided practice routes to check whether you're actually doing your mirror/observation checks before turns, since that's apparently one of the most common reasons people fail. My questions for you lot: is the lack of feedback during private practice actually a problem you feel, or does it not really bother you? Would you trust an app's read on your driving enough to act on it? And honestly — is this something you'd use, or does it sound like a solution to a problem that doesn't exist? Brutal answers welcome, I'd rather hear "nobody wants this" now than after building it.