At the core of the Humapps Database Application Model or H-DAM is the Data-vault, accessible via a browser at data-vault.info
Data-vault is a secure cloud server.
It's where the master copy of data for each H-DAM app is kept.
Access is password-controlled to deliver each app owner to their database(s).
Data-vault is always available to H-DAM apps, which poll it for updates whenever they are in an internet or phone reception area (depending on the user's phone settings).
When a user's local copy of the relevant data is found to be out of sync, just the changes are transferred.
If a local user has entered data, that's also how it gets uploaded.
For the technically minded, the Data-vault is a set of multi-instance servers under AmazonS3 hosting, which has become the global gold standard for app hosting. It has elastic demand response so it can handle any surge in traffic an unexpectedly big success might cause! Top level security and global redundancy are additional advantages.