Thank you very much. The landing page is bought from themeforest (the name is Enovo landing page) then I slightly modified it. I don't want to spend too much time on the landing page as the main focus is the app. I'm not planning to charge in the future. I will try to get sponsors and donations from Patron. I guarantee to you that it will not disappear because I put a lot of effort on the architecture to make it less costly to maintain.