ChatGPT leads with 66.5% implied probability due to its consistent top-two positioning in recent US App Store charts, fueled by OpenAI's July 14 update enhancing search across chats and projects alongside sustained demand for large language model features. Shopping apps like Vinted and Depop hover near 50% on potential seasonal traffic spikes, while TikTok Pro - Events and Threads reflect platform-driven engagement cycles. Google Gemini and Claude trail at lower odds amid slower mobile adoption relative to ChatGPT's established user base. With July 31 just days away, traders are weighing last-minute ranking volatility from any final-week promotions or viral AI capability demos against historical patterns where OpenAI's app maintains strong free-download momentum.