My co founder and i (aka Opus 5.5 and me) have been building https://www.dexbindr.com/ for the past few months now. It started with wanting to complete a pokedex binder but i hated carrying my 11 pounder card binder to card shows. Decided to build this app to help with card pricing, scanning and tracking to get my binder to completion. And apparently people actually do find this useful enough to pay for it so another example where solving your own problem can also help others.