Los Touré and Marc Mueller, two software engineers, call themselves a “boy band.” They’re not making music. They’re making apps. “It’s app music, not rap music,” Touré, whose legal name is Carlos Mayers, told me at his startup’s office in downtown New York City. Danger Testing — which is something between a tech startup and a performance art project — has become Touré and Mueller’s full-time business. After meeting at a tech party in 2024, well …