FaceAi: Swap Faces in Videos represents Koi Apps' entry into the competitive AI-powered video manipulation market, positioning itself as a premium solution for realistic facial transformations. The application leverages artificial intelligence to analyze and replace faces within video content, claiming superior accuracy compared to similar tools available on iOS platforms. The core functionality revolves around a sophisticated AI engine that processes video frames to detect facial structures, lighting conditions, and movement patterns. This technical approach enables the system to maintain consistency across frames while adjusting for variables such as head rotation, expression changes, and environmental lighting. The processing algorithm appears optimized for mobile hardware, though performance may vary depending on device capabilities and video complexity. User experience centers around an intuitive interface that guides users through selection, processing, and export stages. The workflow typically involves selecting source and target videos, with optional manual adjustment points for precision alignment. Real-world usage patterns indicate most users employ the app for entertainment purposes, social media content creation, and experimental video projects, with processing times generally proportional to video length and quality settings. User feedback trends consistently highlight satisfaction with output quality, as evidenced by multiple five-star ratings. Reviewer austinguy54 noted on July 9, 2025, 'this is the best face swap in the market 100% So realistic!!' while Alex Erasmus commented on August 6, 2025, regarding the 'surprisingly accurate' results and 'smooth interface.' These observations align with broader review patterns emphasizing the application's processing speed and output quality. The application demonstrates notable strengths in output realism and processing efficiency but faces limitations common to mobile AI applications, including hardware dependency and potential ethical considerations regarding misuse. Ideal use cases include controlled-environment content creation where subjects have consented to facial manipulation, while professional video production may require additional post-processing for broadcast-quality results.