Bit of backstory: I trained as an audio engineer and spent a couple of years doing sessions at studios, completely skint the whole time. I'd be stood in a room full of unreal gear with no clue what any of it was worth, or whether the second-hand stuff I was eyeing up was a total rip-off.
That feeling never really left me, so I built GearSnap. You snap a photo of any music or filming gear and it tells you exactly what it is, then pulls live eBay + Reverb prices so you know what it's actually worth, it even flags whether a listing's a steal or a con.