Task Coach is a personal organizer, project manager, time tracker, and more. It is cross-platform, supporting GNU/Linux, Windows, and macOS.
There were past integration with an iOS app, but that is not supported any longer. There's no formal Android support either. But there are some ways to sync with any app that uses Todo.txt format though (such as with the FLO Android app, Simpletask).
As of January 2026, the main Task Coach website at http://www.taskcoach.org is outdated.
The main active project is now at https://sourceforge.net/projects/taskcoach/files/