The Forms Management page allows you to manage custom forms:
This area consists of two distinct panes - The left hand pane allows you to add new forms via the (+) button :
You can also access a control to search existing forms:
Or take actions:
The larger right hand side shows recent or pending submissions:
When creating new forms or editing existing forms, You will be taken through a 3 step wizard:
The custom form may be sent to a work item Contact via the main work item page by using the "Attach a form URL" on a new work item note.