After an electric week at the Democratic National Convention in Chicago, Kamala Harris now faces the real test in her bid to be president. Can she convince American voters? In the third part of our series on dating apps, we visit Brazil, China and Pakistan (10:24). And our obituaries editor celebrates the life of Wally Amos, the American king of cookies (19:06).Listen to what matters most, from global politics and business to science and technology—Subscribe to Economist Podcasts+For more information about how to access Economist Podcasts+, please visit our FAQs page or watch our video explaining how to link your account.