OpenTodoList is a todo list and note taking application. It is available for Linux, macOS and Windows as well as on Android. Your information can be shared across devices to keep everything up date date, where ever you go.
Organize todo lists, notes and other items in libraries
Synchronize out-of-the-box with NextCloud, ownCloud and other WebDAV servers as well as Dropbox
Use sync clients of your choice to synchronize with arbitrary services
Schedule items by setting due dates on them
Use Markdown in item titles and descriptions to format text as you like