Editable webform submissions Requirements for user submissions are:


anonymous user is able to submit form data
admin can delete any submission
admin can edit any field of any submission
form can contains fields which are not displayed to user, but admin can edit them
admin can sort and filter the submissions according to one field (date type)


There is webform module, but I do not know if it can solve all those requirements (the first one is OK, ofc ;)
Webform is not necessary for the tasks you've outlined.

Simply create a content type, and grant the Anonymous user role access to create content of that type. 

To have 'hidden' fields which the admin can still edit, you can either hide those fields with CSS, deny access to them via the #access property through a hook_form_alter(), or use the Field Permissions module to restrict access to those specific fields. Note that the Field Permissions module has some performance implications.