See, this is what I keep going on about to my friends - Matrix is actually a graph syncing protocol, not an instant messaging protocol, and is a great way to build federated applications.

I get that Element needs to focus on one use case in order to pay the bills, but there's a lot of room for applications that have barely been explored - calendars, contacts, games, social media, heck - you could build a federated gitlab-like collaboration site with truly federated data. You get multi-device sync, e2e encryption, and identity management out of the box.

Thanks for putting this together, I hope there will be a gold rush as people realize how much low-hanging fruit there is!

> calendars, contacts

I'm interested in this just to keep my devices sync'd up. I know Samsung/Apple/MS etc all have syncing services, but I really really want to get all my data out of their ecosystems.

Just a distributed calendar app would be pretty amazing. No more iCal subscription/export/whatevers, 'just' federate the calendar between devices, and arbitrarily share it with anyone else.

I have no clue where to start with building an app on these abstractions. Does anyone have any pointers? Documentation to read? High level overviews? Etc.?