I've been using Quip for a few months now, it's awesome. Can't really describe it as a Slack competitor because it really has all the core features of Dropbox,

I've been using Quip for a few months now, it's awesome. Can't really describe it as a Slack competitor because it really has all the core features of Dropbox, Dropbox Paper, Google drive-like documents and slack combined. The text editor is extremately pleasant(even when sometimes gets a little crazy, hopefully they fix it soob) which is such a huge accomplishment since, at least on OSX, the app is super smooth, doesn't consume lots of resources and really feels OSX native.