brickdots

Assign/Share a todo item to/with internal users by mentioning them.
<ol>
<li>Mention internal users when an admin wants to assign a todo item to colleagues by typing <code>@</code> when creating a todo item.</li>
<li>Mentioned users would get notification emails. A mentioned user would get an email with the todo item and the link to the edit page that the todo list is on. </li>
<li>Check your todo items on the dashboard. All your todo items (todos mention you) will be on your dashboard. You can go to the edit page by clicking an item.</li>
<li>
Create a todo list in many post types
These are the compatible post types.
<ol>
<li>Posts</li>
<li>WooCommerce Products/Orders/Coupons</li>
<li>Event calendar events</li>
<li>More to come</li>
</ol>
</li>
</ol>

Admin Todotastic

Admins can assign or share todo items attached to a post, a WooCommerce order, a product, and a coupon by mentioning internal users.

melgabmedia

Melgab Project ToDo Board is a lightweight project management and task tracking board built directly into the WordPress admin dashboard.
It allows you to organise projects, manage tasks, track progress and capture notes without needing an external project management tool.
This plugin originally started as a simple replacement for a physical notebook, giving the developer a practical way to capture ideas, tasks and project notes without leaving the WordPress admin area.
Melgab Project ToDo Board is ideal for developers, agencies and site owners
Features include:
<ul>
<li>Create and manage project boards</li>
<li>Add and track tasks within each project</li>
<li>Task types, priorities and statuses</li>
<li>Task updates and progress notes</li>
<li>Task dependencies between tasks</li>
<li>Drag and drop task ordering</li>
<li>Starter example project created on first install</li>
</ul>
Everything runs inside the WordPress admin interface and stores data in its own plugin tables.

Melgab Project ToDo Board

A lightweight project and task management board inside WordPress admin for organising projects, tracking tasks and managing work in one place.

Admin Todotastic vs Melgab Project ToDo Board