Editing/tracking entries on back end

Is there a way to edit and augment entries on the back end to add tracking/status updates. My client would like to mark entries as "approved" once they are processed. Is this something that can be done seamlessly? I assume I could add hidden fields to the form right, then just update them on the back end, but would I be able to have dropdowns to do the editing. I wouldn't want her to have to type "approved" in a text box.

Great! Thanks, I didn't see that in the demo! So if the admin updates these on the back end, can they resend the confirmation and have these additional fields included? Or does only the notes field get included? Basically, we need this: a user would submit a request/form, the admin will update it on the back end and add a reply, and/or info into some admin only fields, and then would want to send out the complete request/form back to the submitter.

Also, how does the "also send this to" dropdown get populated? By just the submitter or other registered users?

Also, are entries stored as custom post types? or is there an easy mechanism to expose entries on the front end to the users who submitted them, sort of like a "my account" type of functionality where they can see all the entries they submitted w/o logging into wp-admin? (but probably logging into WP as a subscriber) I assume this is not a built-in function, but just wondering if it would be easy to add on based on how the core is built.

I'm not able to see admin only fields when viewing entries. It doesn't show up as an editable field.