This project management tool is like a magical customisable to-do list on a single interface, which you can share with others in real-time. Based on a system of ‘cards’, (which are essentially post-it notes), you can categorise and order text, photos, drawings and mock-ups whichever way you want. There’s also a nice progress meter so you can keep an eye on your project’s pipeline, as well as the ability to set appointment reminders. Most brilliantly of all, it’s free.