AI startup Photon announced it has completed a $4.5 million seed funding round co-led by Gradient and A*, with participation from Vercel, HongShan, and others. The company aims to help developers build AI agents that can run on messaging platforms such as iMessage, WhatsApp, SMS/RCS, and email. On September 17, Photon hosted a "Mobile App Funeral" in San Francisco to emphasize its belief that AI agents will replace mobile apps. Photon reportedly has attracted over 40,000 registered developers, achieved a 10x revenue growth in four months, and a 5x increase in message volume last month.