Drafts automatically stores a version history of modifications to each draft. This history can be used to restore a draft to a past version, or simply to review changes. Version history is automatic, no setup is required.
To access a draft’s past versions, get information on the draft using the (i) button in the toolbar, then tap the versions row. Each individual version can be viewed and buttons allow you to copy the content of the version to the clipboard, or restore the draft to that version’s content.