[quote=@BrokenPromise]
I use open writer for all my writing stuff.

Titanpad is also amazing for collaborating, and I was only notified of it's existence about a week ago. It's more or less shutting down in march, but pirate pad looks like it's the same thing. Basically it's a document that you and anyone with the unique url code can edit. It does not send alerts however. otherwise, it's very easy to copy and paste your finished collab anywhere, unlike skype. 
[/quote]

Honestly, I just checked yesterday to set up something on Titanpad and was like, "Damn, that's not gonna work" because of the shutdown. Piratepad is also doable and I suppose we'll see what's up when we get there.

I'm using Trello for an RP right now and it seems to help us create a point to coordinate lore and work up things with notifications for updates to subscribed note items. We're experimenting with it, but you can stick hyperlinks on it (to track where the collabs are) and create checklists.

I've honestly used it for project management before, so it's familiar territory for me. I wanted to create a more collaborative RP where we weren't working in silos, so I settled on trying it for an RP.