Trello is one of the best productivity tools out there and it's free to use. There are apps for all your devices and it's easy to work with others.
Think of it as a 'virtual pin board' where you can attach all the important information you need to be aware of.
It's an amazing to-do list if you need one and it's very effective if you need to keep track of any projects. You really need to sign up to Trello right now