This topic comes up occasionally and we see lots of answers involving plain text and wikis. It seems like there is still room for some perfect solution to the O

This topic comes up occasionally and we see lots of answers involving plain text and wikis. It seems like there is still room for some perfect solution to the OP's problem with just the right feature set. Something with the stellar web and mobile ease-of-use and performance of Trello but document-based and at the same time free-form. OneNote is probably the closest thing that exists.