Thoughts on Magic Form builder
  1.  Very easy to use. 
  2. Like the others you can upload files, receive notifications of a form submission, export to CVS submissions and see the submissions data within the WIX CRM.
Free version only allows for 10 fields and has all but two other from the premium
Premium is $3 and has unlimited fields, unlimited submissions, email notifications and the ability to export form submissions
See full pricing details here