@fryorcraken asked me what do I think about his Reliable Channels implementation and whether I can use it for my apps. My answer was, let me try first… Well, I tried:-)
Let me introduce Scala - Secure CALendar App - an implementation of a simple calendar application which uses Waku Reliable Channels to maintain the state and sync of shared calendar.
It is a one-day-hack, so bear that in mind when you get frustrated with it and start thinking about what all is missing or not working as you’d wish:D
The key feature/factor is that when you share the calendar, a Waku SDS based Reliable Channel is initiated and every modification of that calender is published on Waku - by using SDS, users can be sure they eventually get all messages and hence land on the final state of the calendar.
There is no authn/authz at this moment - which means that all shared calendars are public and editable by anyone with a link - depending of whether there is interest, I might add some wallet based features for this.
Fun thing - this app has been completely written by AI - I have not even looked at the code 
. They way I integrated Waku was by providing Lovable with a good example - Franck’s Retro Chat - this let AI analyze some simple working code and then replicate it in the Calendar app, while being able to use it for more complex architecture - because Retro Chat only works with a single channel, while in Scala each shared calendar is one channel and it has to setup and maintain them all.
Anyway, let me know what you think, submit issues and keep on hacking!
Code: GitHub - vpavlin/scala
Deployment: https://preview--sync-shards-cal.lovable.app/
Example Shared Cal: Scala - Secure CALendar App