Trello

Trello is a SCRUM like free online application.

Features

Free
Create your own list of actions, as many as you like
Receive email notifications: Instantly, Periodically, Never - https://trello.com/my/account
Subscribe to card changes
Activies/Notifications can be visualized, by visualizing the public JSON - e.g. https://trello.com/board/4f46dfd8251057f904f99550/ose-video.json
Add Deadlines
Add People
Add Colors
Add Comments
Upload files
Vote for an action
Active Developers
Has shortcuts: https://trello.com/shortcuts
You can move cards between Boards!
REST API - Card, API
Android and iOS applications.

These are guidelines how to use Trello collaboratively:

Create needed Lists, e.g.: TODO, Doing, Verification, Done.
Create new cards:
- Press "N" to create a new card. It will be created below the current selected card. Type the name of the card and press "Enter" to save it.
Assign yourself/another to a card
- Assign yourself to a card - select the card and press "SPACE"
- Assign another to a card - select the card and press "a" and choose the person.
- Unassigning works with the same shortcuts.
Verification
- Add card for Verification
  - Add the card in the "Verification" list and assign the person, if not already assigned, to verify it (press "A" and choose the person).
  - Send email to the person with subject "Verify <card name>" and in the body link to the card (e.g. https://trello.com/card/animating-low-cost-explanation-sasha/4f46dfd8251057f904f99550/94)
- Verify a card
  - If all okay, move it to the list "Done"
  - If more work is to be done:
    - Create a checklist and the points that has to be done
    - Move the card back to "TODO" or "Doing"
    - Send email to the person responsible with subject "TODO <card name>" or "Doing <card name>" and in the body link to the card. He should read your checklist points and fix them.
View more cards by decreasing the font size from your browser.