ToDowl is one workspace for the things a day is actually made of: tasks, calendar, notes and money. They share the same projects, so a deadline on the board also shows up on the calendar. The free plan covers unlimited tasks and notes with no card, and up to 3 projects. Pro adds the calendar, the assistant, folders, sharing and full history.
We kept losing tasks between a to-do app and a separate calendar, so we built one place where tasks and time blocks live together.