I use iA Writer on iOS, coupled with nvAlt on Mac. They both read/write from the same dropbox directory. You might also like Drafts for iOS - it's really more

I use iA Writer on iOS, coupled with nvAlt on Mac. They both read/write from the same dropbox directory. You might also like Drafts for iOS - it's really more for write --> push to x service, but it does that really well.