We’ve released a new beta with functionality that allows edits to finalized or sent submissions on the device 
Edits on device are off by default and configurable in form design.
We still have a lot of work to do! Here are some additions we have planned before release:
- Change the end of form message to indicate that the submission will still be editable
- Only allow edits to the last edit in a chain
- Identify related edits in the form listings
- Show a helpful error message when the submission is edited on the server and an attempt to edit in Collect is made
- Better handle the case where drafts are disabled in settings
You can now try out the basic functionality by modifying the form XML. You can use client_editable.xml (846 Bytes) or you can edit any existing form and add <submission odk:client-editable="true"/> directly inside the model block. To get form XML for any existing form, you can use the "Form definition" dropdown in Central. Download and open the simple example linked above to see the full structure.
This should now let you edit submissions of that form only and see the edits tracked in Central.
This functionality will soon be available from the XLSForm settings sheet. Read more in the spec design thread.
On the next Insiders call, May 7th, we will demo how it works, discuss how it might fit into different workflows, and answer Insiders' questions.