Phoebe Gates cofounded Phia, an AI shopping assistant, with her Stanford University roommate Sophia Kianni. The shopping assistant plugs into browsers like Chrome and Safari to compare prices and surface deals across tens of thousands of retail and resale sites in real time. It essentially serves as your own personal deal finder: say you’re looking at a $200 dress from Anthropologie, Phia can find and compare prices at second-hand sellers to help customers find a better price.

That's actually a neat premise. Fashion isn't my cup of tea, but otherwise that sounds useful (albeit not very unique; shopping assistants are a dime a dozen).