1) Get the WebHook URL (under your help tab->integration) and paste it into the WuFoo WebHook url:
2) Fill out the form. Enter the Heap field you want the data to land in. If the WuFoo "special" form field doesn't allow you to do that, just enter valid example content (e.g any valid e-mail, any valid phone number, etc.):
3) Heap detects that it received some data that wasn't properly mapped, but it seemed like it could be, so it sends you an e-mail:
4) Paste the remap text into the HandshakeKey field in WuFoo.
Now, any form post will be placed in the proper fields in Heap. This method works with any web app that supports a remap or HankshakeKey field.