AD Client "Permissions to other applications" WebAPI missing

I'm having difficulty using Azure AD to make Azure Web APIs available to native clients. I've tried using the Microsoft documentation, and Vitorrio Bertocci's Channel 9 "Azure Identity 106" example. 

Using VS 2013 Community I added a Web API called "WebAPI1"using my Azure AD Domain authentication. I verified the Web API shows up in Azure AD, and the manifest was generated with oauth2Permissions.

I then added a test "Native Client Application" called "MyClient" to the Active Directory. I tried to add "WebAPI1" to the new client entry by selecting "MyClient" > Configure > "permissions to other application" > "Add Application" > Show All Apps

But, "WebAPI" does not appear as a selection. (I pasted the "WebAPI1" oauth2Permissions from its manifest below)

Apps show up, but not Web APIs.

  "oauth2Permissions": [    {      "adminConsentDescription": "Allow the application to access WebAPI1 on behalf of the signed-in user.",      "adminConsentDisplayName": "Access WebAPI1",      "id": "213c955f-5ae2-4502-8790-dc17b5bd5a7a",      "isEnabled": true,      "type": "User",      "userConsentDescription": "Allow the application to access WebAPI1 on your behalf.",      "userConsentDisplayName": "Access WebAPI1",      "value": "WebAPI1_user_impersonation"    }  ],