Another contract made a Facebook messenger group and shared all versions of files by pasting them in to the messenger chat.
Wasn't particular happy about those but fortunately both were fairly short term things and to be honest I couldn't really think of anything better that I believe I could convince them to do. The Line accountant was definitely not going to use anything other than Line.
The FB Messenger file sharing, well, what. Email? Dropbox cost $$$ per user. Github requires more training. I suppose maybe Slack would have been better than FB messenger but still requires getting the other party to install apps and get used to a different workflow, So yea, I just put up their chosen method of communication for the duration.
And despite this vast monopolistic ecosystem DaumKakao put ads in the app this year. Greedy.
"Please turn in your assignments via Snapchat by 7AM tomorrow"