ToDoList, TickTick, Google Tasks, Org mode, Vikunja, Task Air, myTinyTodo, 2Do, GTasksTo-Do List, ZeroTodos, Task Coach, sleek, Focus Matrix, Todorant, Godspeed, WeekToDo, Taskito, Lunatask, ToDoBook, Hero Panel, My Brain, OpenTasks, Getting Things GNOME, Sometime, Tinotes, Instapush, Taskary, Challenge Achieved, Tasque, To Die List, Astrid, Actiontext, Taskfully, Todo Reminder with Alarm, Wunderlistux, TodoListProject.com, Nibras PKM, TaskFabric Cloud Projects, Laterbox, Taskforce, PopDo, To Due, Kalendar, MonoCorpus, Kocpit, TimeIO, Gluru, TaskOnBot, DayTasks, Paper Bullet, Todoman, jdotxt, Mirakel, Cloudship are some alternatives to Tasks.org.