Hi @Mindphreaker, I think an example of this is what happens with the email app inbox MD, there are other cases in the apps where we also use this technique, but this one is quite simple to review if that’s what you need.
The email app creates the inbox MD at a random address when you create your email ID:
https://github.com/maidsafe/safe_examples/blob/master/email_app/app/safenet_comm.js#L211
It then serialises it:
https://github.com/maidsafe/safe_examples/blob/master/email_app/app/safenet_comm.js#L259-L260
…and it then stores it in its own container, the app’s own container:
https://github.com/maidsafe/safe_examples/blob/master/email_app/app/safenet_comm.js#L161-L162
When you open the app from another device, or even from the same device after restarting the email app, it goes and gets the serialised inbox from it’s own container, it deserialises it, and after that it can action on it using the MutableData functions:
https://github.com/maidsafe/safe_examples/blob/master/email_app/app/safenet_comm.js#L137-L138