On April 18, 2020, DDI Lab launched a webpage (https://ddi.sutd.edu.sg/when-will-covid-19 end/)  (screenshot in Figure 1) to share data-driven predictions of the next developments and end dates of COVID-19 in different countries and has been continually updating the predictions daily with the latest data. For each country, a simple figure is provided to visualize the estimated pandemic life cycle together with actual data to date, which further reveals the predicted inflection point and ending phase. The prediction was started purely for self-curiosity regarding when COVID 19 might end in Singapore where we live and then has been expanded to cover other countries in response to requests of site visitors. Since April 18, the site has unexpectedly received millions of visitors from all over the world. This paper explains the motivation, theory, method, data and cautions for the predictions.