My idea is to create a slack app which allows to mark important messages ( by admin / channel owner) and later on send on daily / weekly basic to all channel's participants.
Do it! I could see that being useful for teams.
Does anything like this already exist? I seem to remember seeing a "rollup" type product for Slack a while back but can't remember.
Didn't find it, but I guess it would be extremely helpful in my company :)