Confused with how to manage the actual .sketch files
I'm up & running with Kactus using BitButcket.  I'm able to add commits, push & pull changes to the  Kactus folder that contains all the .json etc.  My question is how to manage the actual .sketch file itself.

When setting up Kactus I accepted the recommended setting of ignoring .sketch files.  So assuming I am collaborating on work with another remote designer - how do we go about sharing the actual .sketch file as it's not in the repo?    Setting up Bitbucket and Kactus itself was pretty straightforward, but I'm unclear on the relationship between my regular .sketch file and the ".json folder' created by Kactus.  

- How does the Sketch file update the .json folder after I've made changes in Sketch (is this what the Kactus app does?)
- If I've accepted the recommended setting in Kactus of not tracking .sketch files, how does my remotely located colleague access the .sketch file after they've cloned the repo?  
- Should I email my colleague the .sketch and ask them to add it to their local repo, or is it just easier to ignore the recommended setting in Kactus and have the .sketch file pushed to BitBucket?

One final question - what are the subscription packages about please?  Is there a difference between the binary on Github and the one available via Kactus.io ?

Many thanks,