I&#x27;ve been an avid user of Trello. Easy to use, very simple for any external stake holders to get into (and nice permissions) while being super simple to use. They&#x27;ve got a great amount of &#x27;example&#x27; boards as well: <a href="https:&#x2F;&#x2F;trello.com&#x2F;inspiringboards" rel="nofollow">https:&#x2F;&#x2F;trello.com&#x2F;inspiringboards</a>