first commit

Nitrox.Launcher/Models/Exceptions/DuplicateSingularApplicationException.cs

@@ -0,0 +1,10 @@
+using System;
+
+namespace Nitrox.Launcher.Models.Exceptions;
+
+public class DuplicateSingularApplicationException : Exception
+{
+    public DuplicateSingularApplicationException(string applicationName) : base($"An instance of {applicationName} is already running")
+    {
+    }
+}