When you said hopefully to include player campaign notes, I thought of kanka. It's somewhat less feature-rich, I think, but it is potentially-free and collaborative. Source: almost 2 years ago

Our group has been using Kanka (https://kanka.io/en) for the past few years and it’s been super helpful. Source: almost 2 years ago

Some people I know have recommended kanka: https://kanka.io/en. Source: about 2 years ago

I use Kanka, I’ve found it to be excellent. A few key points: - there are loads of different page types you can create, characters, locations, organisations, items, it’s quite varied. Although you can’t make custom ones I’ve never needed to. - you can easily link to other pages within your Kanka campaign by typing and @ followed by the name of the page, so @Barry will pop up a list for you to select from your... Source: over 2 years ago

I've also heard some pretty good things about Kanka (https://kanka.io/en), though I haven't tried it myself yet. Source: over 2 years ago

Diagrams and visualizations are often indispensable when explaining complex concepts or designing system architectures. Excalidraw and Whimsical are two popular quick drawing tools that allow developers to create diagrams easily. With their simple yet powerful interface, developers can create wireframes, flowcharts, and other visual representations in no time. These tools are great for both brainstorming ideas and... - Source: dev.to / about 1 month ago

Whimsical.com - Collaborative flowcharts, wireframes, sticky notes and mind maps. Create up to 4 free boards. - Source: dev.to / 4 months ago

Whimsical is amazing. https://whimsical.com/. - Source: Hacker News / 6 months ago

If only I could figure out how to handle branching in Mermaid like the "Saving" node in this animation: https://whimsical.com/. - Source: Hacker News / 8 months ago

The aesthetics of those diagrams strongly remind me of whimsical: https://whimsical.com. - Source: Hacker News / 8 months ago