Once you move to Cc you’ll never go back to paper lesson plans ever again. Cc’s flexible templates make adding standards, rearranging activities, and every other part of lesson planning efficient, powerful, and collaborative.
Common Curriculum is an online lesson framer that reminds me of Trello. There is a free level you can use to get familiar with the tools, but things get more interesting on the paid tiers.
On the paid tiers, teachers can collaborate on the lesson plans and also have access to a Units calendar type.