C9Project

C9Project is a simple and easy to use project management service focused on team collaboration.
To use C9Project, you don't need to be a project management professional. All you have to do is to form your team, break down the project into tasks and assign each of these tasks to a team member. Then, let your team members update the task progress and you will get the summary of the project.

Registration is required to use the app. It is free and allows user to hold one project and a team of maximum three team members.
Once registered, you can invite people to join your team (number of team members depends on the subscribed service level) and can also be a team members of other users at the same time.

To start a project, just add a new project with basic information such as project name, start and due date, priority, etc. A project checklist is also provided for any prerequisite that need to be met. Then, insert project task with information like task name, start and due date, expected man-days, priority, contribution to project and team member assignment. Once assigned, team members can update their tasks progress, used man-days and remarks accordingly on their apps. Project owner can always get the current project's progress and summary through project details. [If allowed to receive push notification, project owner will be notified on progress update.]