@iMeddles
For now it's single device, but we're working on multi-device support. Our approach is to handle sync through the relay rather than backups. Each phone would run its own server independently and receive activities from the relay, which could also store lightweight sync data like read positions.
@apps

Having a TTL for your messages, is that something you'd expect? We could introduce an option to automatically delete your posts after a delay (disabled by default, it would be up to you to set your default TTL). We could also allow setting a TTL when composing, so you can customize it at the post level.
The app needs to be online to send the Delete activity to other instances. That said, #Holos already supports pending offline activities.
What do you think?

#HolosSocial