Ryan Serhant believes his new app will make day-to-day work easier for real-estate agents.Crystal Cox/Business InsiderRyan Serhant's firm raised $45 million from Camber Creek and Left Lane Capital.Much of the money will go toward growing the firm's AI platform, S.mple.S.mple isn't Serhant's first app. He told BI how he turned past failures into success.Despite Ryan Serhant's standout 2024, he hasn't escaped failure.