Marked as 'AdvertsingProfitControl 0.9.5.2' by its folder. I believe this version is where most of the main interface for the user was complete and I was toying with the idea of allowing the user to change the shrink on the main form.

AdvertsingProfitControl/FrmLogConsole.cs

@@ -7,8 +7,7 @@ namespace AdvertsingProfitControl
     public sealed partial class FrmLogConsole : Form
     {
         //Source code: https://hashfactor.wordpress.com/2009/03/31/c-winforms-create-a-single-instance-form/
-        private static readonly FrmLogConsole gLogConsoleInstance = new FrmLogConsole();
-        private static bool gIsShown = false;
+        private static bool _gIsShown;
 
         public FrmLogConsole()
         {
@@ -18,16 +17,18 @@ namespace AdvertsingProfitControl
             logListView.View = View.Details;
             //Information for drawing header columns and sub-items in ListView:
             //http://stackoverflow.com/questions/561798/how-do-i-align-text-for-a-single-subitem-in-a-listview-using-c
-            ColumnHeader header = new ColumnHeader();
-            header.Text = "Advertising Profit Control " + Application.ProductVersion + " Debug Console";
-            header.Name = "LogConsoleHeader";
-            header.Width = logListView.Width;
+            var header = new ColumnHeader
+            {
+                Text = @"Advertising Profit Control " + Application.ProductVersion + @" Debug Console",
+                Name = "LogConsoleHeader",
+                Width = logListView.Width
+            };
             logListView.Columns.Add(header);
         }
 
         static FrmLogConsole()
         {
-            GetStaticInstance.FormClosing += new FormClosingEventHandler(LogConsole_FormClosing);
+            GetStaticInstance.FormClosing += LogConsole_FormClosing;
             //Set the maximum and minimum size of the form.
             GetStaticInstance.MaximumSize = new Size(900, 900);
             GetStaticInstance.MinimumSize = new Size(400, 400);
@@ -35,27 +36,25 @@ namespace AdvertsingProfitControl
 
         public new void Show()
         {
-            if (gIsShown)
+            if (_gIsShown)
             {
                 base.Show();
             }
             else
             {
                 base.Show();
-                gIsShown = true;
+                _gIsShown = true;
             }
         }
 
         public new void Hide()
         {
-            if (gIsShown)
-            {
-                base.Hide();
-                gIsShown = false;
-            }
+            if (!_gIsShown) return;
+            base.Hide();
+            _gIsShown = false;
         }
 
-        public enum Level : int
+        public enum Level
         {
             Critical = 0,
             Error = 1,
@@ -68,7 +67,6 @@ namespace AdvertsingProfitControl
         public void WriteToLog(Level level, string message)
         {
             Color color;
-            int index;
 
             switch (level)
             {
@@ -87,14 +85,17 @@ namespace AdvertsingProfitControl
                 case Level.Verbose:
                     color = Color.Blue;
                     break;
+                case Level.Debug:
+                    color = Color.Black;
+                    break;
                 default:
                     color = Color.Black;
                     break;
             }
-            index = logListView.Items.Count;
+            var index = logListView.Items.Count;
             try
             {
-                message = String.Format("{0}: {1}", level, message);
+                message = $"{level}: {message}";
                 if (level != Level.Info)
                 {
                     GlobalClasses.WriteToLog(DateTime.Now + ": " + message + Environment.NewLine);   
@@ -107,13 +108,17 @@ namespace AdvertsingProfitControl
                 MessageBox.Show(e.Message);
             }
 
-            if (level == Level.Critical)
+            switch (level)
             {
-                logListView.Items[index].BackColor = Color.Red;
-            }
-            else
-            {
-                logListView.Items[index].BackColor = Color.WhiteSmoke;
+                case Level.Critical:
+                    logListView.Items[index].BackColor = Color.Red;
+                    break;
+                case Level.Error:
+                    logListView.Items[index].ForeColor = Color.Maroon;
+                    break;
+                default:
+                    logListView.Items[index].BackColor = Color.WhiteSmoke;
+                    break;
             }
         }
 
@@ -121,17 +126,11 @@ namespace AdvertsingProfitControl
         {
             e.Cancel = true;
             GetStaticInstance.Hide();
-            gIsShown = false;
+            _gIsShown = false;
         }
 
-        public static FrmLogConsole GetStaticInstance
-        {
-            get { return gLogConsoleInstance; }
-        }
+        public static FrmLogConsole GetStaticInstance { get; } = new FrmLogConsole();
 
-        public bool IsVisable
-        {
-            get { return gIsShown; }
-        }
+        public bool IsVisable => _gIsShown;
     }
 }