Before the pandemic, Yiying Lu was known for her work designing the Twitter Fail Whale and the dumpling and boba tea emojis. In the past few weeks, Lu said she was called to a higher purpose. From her apartment in San Francisco, she toiled away in a Slack channel with two dozen people she has never met to create a free website called Corona Carecard. It asks Americans to buy gift cards to their favorite local shops, providing a much-needed source of income while stores are shuttered.