The event script, always up to date. People with permission edit it; everyone with a link always sees the latest version, with no account and nothing to install; people who organise events sign in with an account. What is happening now and what comes next show up in blue.
Install from your script's link: the installed app reopens the last script you looked at. It is a web app (PWA): it doesn't go through the Play Store or the App Store and it updates itself when it opens with a network connection.
Screenshots with a demo event and made-up names (the screenshots show the interface in Portuguese).