That's Outlook Tasks, not a "task/app manager"

It (pretty much) replaces all the functionality of the built-in Tasks application. It adds the ability to nest tasks under one another

Based entirely on properties of the built-in Tasks - will sync with Exchange/Outlook, and requires no importing of Tasks

Installation:

Copy the Nested_Tasks.cab file to your device
Run it

General Usage:

On first use no Tasks will be nested (obviously)
Tap-and-hold on an item to be nested (the "Child"), choose Cut from the context menu
Tap-and-hold on an item to become the "Parent", choose Paste Here

Nested Tasks Features:

- Cut and Paste tasks to create nesting
- Add new, edit and Delete tasks
- Copy tasks to create duplicates
- View and set task Priority from the menu
- Complete or Activate Tasks with the checkboxes