Run single instance process from console.

main.cs

[STAThread()]
static void Main(string[] args)
{
  Console.Title = "Call App";
  // hide the console window
  setConsoleWindowVisibility(false, Console.Title);
  // look for all running instances of the app
  var runningProcessByName = Process.GetProcessesByName("notepad");
  
  if (runningProcessByName.Length == 0)
  {
    Process.Start("notepad.exe");
  }
  else
  {
    SetForegroundWindow(Process.GetProcessById
    (runningProcessByName.ElementAt(0).Id).MainWindowHandle);
    ShowWindow(Process.GetProcessById
    (runningProcessByName.ElementAt(0).Id).MainWindowHandle, 1);
  }
}