That is the m5go default program that comes with the firmware. The black screen with Upload, AppList, and Setup has a 1 second timeout. So just reset your M5Stack by pressing the red button on the side and then within 1 second, press the AppList button to get a list of other pre-built apps that come with the firmware. Or if you want to run your own program from UIFlow, press the Upload button within 1 second.
Another tip, if you want the M5Stack to launch your custom program by default (after the 1 second timeout), then use the Download feature of UIFlow, which is found here.