Traders assign roughly even odds near 50% across several unnamed contenders for the #2 free US App Store spot on September 18 because daily download velocity remains fluid among AI productivity apps and marketplaces. Muse from Meta has climbed rapidly following its launch, posting strong initial US downloads that place it near the top in recent charts, while Vinted and TikTok Pro - Events maintain consistent momentum through user engagement. ChatGPT holds a firm #1 position, leaving the second slot open, with Google Gemini and Google Maps trailing at lower implied probabilities due to steadier but less explosive growth. Short-term catalysts such as feature updates or marketing pushes could shift rankings before resolution.