Rolfe Winkler / Wall Street Journal : Comparing ChatGPT's mini-apps with native iOS apps: some like Uber, OpenTable, and TripAdvisor fell short with frequent error messages, but Instacart did well —  ChatGPT apps are a key piece of OpenAI's long-shot bid to replace Apple.  Many aren't yet useful.  —  Sam Altman wants OpenAI to have an app store to rival Apple's.