They can also be viewed using the "Enterprise Applications" section of the AzureAD/Azure Portal.
Unfortunately if you don't know the name the UI will only show the first 50. It also doesn't seem to show secrets/expiry.
Tested the snippet below in Visual Studio:
var ctx = new ClientContext(siteUrl);
List olist = ctx.Web.Lists.GetByTitle("MyList22");
ListItemCreationInformation creationItem = new ListItemCreationInformation();
ListItem lstItem = olist.AddItem(creationItem);
var teststring = "";