Which app has USDT?

Could you recommend any apps that support USDT transactions? As a professional in the field of cryptocurrency and finance, I'm keen on exploring platforms that offer secure and efficient USDT trading options. It would be great if these apps also provide additional features like portfolio tracking and market insights. Moreover, I'm also interested in knowing if these apps have any user-friendly interfaces and reliable customer support. Could you please elaborate on the available options and their respective advantages? Your insights would be highly appreciated.