Where can I view different form modes? I created a simple content type and a form mode for this content type. Where can I view this form mode after creating it? I see no option for form modes when creating a content type.
I would have expected an option to be presented when clicking on "Add Content" to select "Add xy content with xy form mode"? Raised it as an issue here https://www.drupal.org/node/2530086
You can try these modules.

https://www.drupal.org/project/form_mode_control https://www.drupal.org/project/form_mode_manager

I prefer form_mode_control. Form_mode_manager create a view form mode for all content types.

These modules can be restricted with permissions. But I prefer https://www.drupal.org/project/field_permissions; it is more acurated by field.