ChatGPT has become the top free app in the US Apple Store, driven by the release of OpenAI's GPT-5.5 Instant model. This new version introduces memory capabilities that enhance user interaction by revealing part of the context influencing responses. The update replaces the previous GPT-5.3 Instant model and is expected to significantly increase user engagement and app downloads. The market has shown strong confidence in ChatGPT's ability to secure the top position, with a 100% YES pricing for its ranking by May 5. OpenAI's strategic updates, led by CEO Sam Altman and VP of Product Peter Deng, are crucial for maintaining a competitive edge in the AI app market. Observers are advised to watch for user feedback on the new features and any official statements from OpenAI regarding the update's impact on download metrics.