There is also Dropbox Paper.. but there is no native app yet and their development efforts are a bit slow.
I guess it comes down to personal preferences and wants/needs. I personally have no issue with them using my iCloud account and have always found the idea of a monthly quota "odd". If I am paying for a service, I would expect to be able to use it as much or as little as I like.
Wasn't there another app that worked over the top of Evernote to provide markdown support? Could that be an option?