Task Scheduler for ios (project timing)?

Question

iOS

On Windows I had such a program ToDoList or TaskList, where you could create a list of tasks with checkboxes and create subtasks for each task. For example, the first task is to change the shopping cart on the site, and then you detail that this stage includes changing scripts, changing the code, changing the style, and then to change the style you create several more subtasks and so you detail the general tasks to infinity, and then for each subtask you prescribe the time for its implementation, as a result, the total time is calculated for the parent task. I have already rummaged through a bunch of programs on the AppStore, but they are all somehow inconvenient, either the time is not summed up there for the parent from the child elements, or there are no checkmarks for the tasks.

Answer 1

Trello
https://trello.com/
https://itunes.apple.com/us/app/trello/id461504587?mt=8

Answer 2

Look at toodledo,
there are also subtasks, there is also a runtime
+ multi-platform