Credit Card Selector
An iOS app that tells you which of your credit cards to use at any store. The part that turned out interesting is getting your targeted bank offers (Amex Offers, Chase Offers etc) without a bank login: a Safari extension reads the offers page you're already signed into in your own browser session, and can tap all the little "add to card" buttons for you. Chase renders theirs inside shadow DOM in a virtualized grid so only the visible tiles exist in the DOM at any moment, which made scraping it way more annoying than it had any right to be. Solo project, about a year in.